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Frequently Asked Questions

What is the purpose of XtraMath?

XtraMath helps students transition from counting or calculating the basic math facts to recalling them. Recalling math facts instead of calculating them frees up mental resources for higher-level operations.

XtraMath uses timed quizzes and practices to encourage students to answer the questions as quickly as possible combined with spaced repetition to efficiently develop recall. The three-second threshold is carefully selected to be long enough to type in a recalled answer but not long enough for the student to comfortably enter a counted or calculated answer.

Students should have already learned the basic counting or calculating strategies and be able to solve the problems without time pressure before starting to practice an operation on XtraMath.

For more information on XtraMath you can watch the overview videos on our home page and additional videos in the Learn More section of our website.

Enrollment, Sign-up and Sign-in

One of my children is using XtraMath through school. Can my other children use it too?
Sure! Sign in to your parent account that was created as a result of enrolling your first child. Then click "Add child" in the left column to create student accounts for your other children.
How do I handle a student that lives in two households?
Copy the student's parent flyer (or print another one) and send it home to the second household. Both parents can go through the enrollment process and will be linked to the same student account. The student can use either parents' email address to sign in and will use the same PIN number.
I've lost my child's PIN number. How can I retrieve it?
Sign in to your parent account and click on the student's name. The PIN number is shown at the top of the student report. The student can sign in with the e-mail address used for the parent account, their name exactly as shown in the parent account, and the PIN number.
I'm a teacher using XtraMath at school. Can I also use XtraMath with my own children at home?
Of course. Sign in to your teacher account and click the "Account" menu item. Click the checkbox that says, "I am a parent...", then click "Update". That will add a "My Kids" tab to your account that you can use for your own children. Select the "My Kids" tab and click "Add child" to create accounts for your children.
My child used XtraMath last year. How do I set them up this year?
The process is the same every year. Your child's new teacher should print out the parent flyers for their new class and send them home. When you follow the directions on flyer it will link your child's existing account into their new class. Your child will get a new PIN number but all of their past progress is preserved.
How do I change the email address associated with my XtraMath account?
Sign in to your parent or teacher account, click on the "Account" menu item, then on the "Email" tab. At the bottom is a form to change your email address.
How do I convert my parent account into a teacher account so I can use XtraMath with my class at school?
Sign into your parent account and click the "Account" menu item. Click the checkbox that says, "I am a teacher..." Enter the name that students use to address you at school and click the "Update" button. Your child's report is kept separate from your class under the "My Kids" tab.
How do I remove another teacher's name from the classroom sign-in page?
Click the "X" button to the right of the teacher's name to remove it from the classroom sign-in page. You will need to enter a classroom code to confirm the removal. (This prevents students from removing teacher's names.) To look up your six-character classroom code sign in to your teacher account and click the "Account" menu item.

Student Activities

Can I change the operation that my student is working on?
If your child is using XtraMath at school then check with the teacher before making any changes. We recommend students master the operations in their natural order. Students cannot, for example, quickly calculate the answer to a multiplication question without having addition facts mastered. Also, it is important that students not practice facts until they have a good conceptual understanding of the operation. With those caveats in mind, a parent or teacher can change the operations assigned to a student. To do so, sign in to a parent or teacher account. On the student's report click "Change program" in the left column.
Can students do XtraMath more than once per day?
Students can sign in to XtraMath multiple times per day however once per day is the recommended amount. Additional sessions have diminishing educational value and they decrease students' enthusiasm for the program. Once per day as regularly as possible is the key to making good progress.
XtraMath goes too fast for my child. Can you slow it down?
XtraMath is designed to measure what basic math facts students can recall, not what they can calculate. Three seconds is a carefully selected compromise that is long enough that a relatively slow typist can enter a recalled answer, and short enough so that most finger-counted responses are not erroneously considered fluent. If you increase the interval then you are no longer measuring fluency.

Most students get pretty good at typing numbers after only a few sessions of XtraMath. If you're concerned that typing speed is a problem then you could have your child practice number typing prior to using XtraMath. A Google search will turn up many number typing games. For students with fine-motor difficulties it is okay for an adult to type in numbers on behalf of the child.

For maximum effectiveness XtraMath adjusts to each student and has them practice near the limit of their abilities. This might be uncomfortable for some students. If students do not get the correct answer within the three second threshold they should not perceive it as a personal failure but as a normal challenge of the XtraMath "game".
XtraMath says my student is "done". Can they continue to use XtraMath?
If a student is in third grade or below then you could assign them an operation above their grade level. Ensure the student has a good conceptual understanding of the operation before having them practice it. For students that have completed all four operations you can assign them an advanced program. In the advanced programs students are given a shorter amount of time to answer questions. See the instructions in this section on how to change the operation that a student is working on.
What operations will my student practice?
By default kindergarten and first grade students get addition only. Second graders also get subtraction. Third graders also get multiplication. Fourth graders and above get division, too. See the instructions in this section on how to change the operation that a student is working on.
My child is struggling with XtraMath. What should I do?
Here is what we recommend you tell your child if they are struggling with XtraMath:
  • XtraMath takes only a few minutes each day, but it requires your undivided attention during that time. Stay focused on the problems and do your best every time.
  • Do not feel hurried by the clock. Accuracy is more important than speed, but once you have the answer you should type it in promptly.
  • Do not worry about the occasional typo or mistake. You will have many more chances to answer that same problem in the future.
  • Do not guess. Try to remember the answer first, and if you cannot remember it then calculate it.
  • Whenever Mr. C. shows you the correct answer take a second to repeat the problem and answer to yourself. This will help you remember it in the future.
  • Never, ever enter wrong answers on purpose. If you do your score will drop significantly and it will take you several sessions to prove what you already know and get back where you should be.
  • It can take two months or more of regular practice to master an operation so be patient and be persistent.
  • Do XtraMath as regularly as possible while following this advice and you will make good progress.
We have endeavored to make XtraMath work well for as many students as possible. However, it may not be the right solution for your child. If your child continues to struggle with XtraMath please consult your child's teacher for effective alternatives.
My child is distracted by Mr. C. during "Race the Teacher". Can I remove his image?
On the web and in tablet apps there is a button in the lower left corner of the practice activity that will turn off the images of Mr. C. (or turn them back on). Phone apps don't have that button but the setting is persistent for each student. A student can turn Mr. C. off on the website or tablet app and the next time they sign in on a phone Mr C. will not appear in "Race the Teacher".
What if a student has to leave in the middle of doing XtraMath?

XtraMath takes only a few minutes and it is best if the student can complete it in one sitting. Students should not start XtraMath if they will have less than ten minutes or so at the computer.

If a student doing XtraMath on our website needs to leave in the middle of a session they can click on the XtraMath logo to sign out.

On an iPad or iPhone simply pause and resume XtraMath twice in succession. To pause press the physical Home button and to resume tap the XtraMath icon on the home screen. The first time you resume you will go back to where you left off. This allows students that accidentally press the home button to resume their session. The second time you resume XtraMath in a row it will exit the student activity and return to the XtraMath home screen.

XtraMath sessions are divided into two-minute activities. If the student signs out in the middle of an activity then they will have to repeat that activity. If the student can finish their current activity and continue on to the beginning screen of the next activity before signing out then they will not have to repeat anything.

Will XtraMath work for my child with special needs?
We have not (yet) put any accomodation in XtraMath for students with special needs. There are some special ed. teachers using XtraMath with their students. Because needs and circumstances vary considerably we cannot make a recommendation one way or the other. If you have specific suggestions on how XtraMath could be modified to work for students with special needs please let us know.

For students that find the number typing difficult it is perfectly acceptable to have the child say the answers and a parent or sibling type them in.
Why isn't Mr. C. talking anymore?
During the first few sessions the teacher, Mr. C., explains to the student how the program works. After that there really isn't anything else to explain so he only appears as a still picture.
Isn't dividing zero by a number undefined?
You can't divide a number by zero but you can divide zero by a number that is not zero. Using a sharing example, a dozen donuts divided among four people is three donuts per person, 12 ÷ 4 = 3. Zero donuts divided among four people is zero donuts per person, 0 ÷ 4 = 0 -- an unhappy situation but well-defined. A dozen donuts divided by zero people, 12 ÷ 0, doesn't make sense and is undefined. In division XtraMath has zero as a dividend, 0 ÷ n but never has zero as a divisor, n ÷ 0.

Parent and Teacher Reports

What do the colored dots mean on the reports?
Progress Graph
Click on the ? button in the upper-right corner of the report to pop up a key that explains the colors. Green means the student got less than 10% wrong. Yellow means between 10% and 25% wrong. Red means over 25% wrong. Blue dots indicate an incomplete XtraMath session. Students that regularly get red dots should be encouraged not to guess at answers. If they cannot confidently remember the answer they should do their best to calculate or count the answer.
What is the mastery score shown on the reports?
Progress Graph
The mastery score should be interpreted as "percent complete" for an operation. It is a weighted percentage of facts that the student is answering correctly in under 3 seconds. Easy facts such as +0, +1, ×0, ×1 count a bit less than one. More difficult facts count more than one.
What does the mastery matrix mean on the student reports?
Progress Graph
The mastery matrix color-codes every fact of an operation. A green square means the student is answering that fact reliably in under three seconds. A yellow square means the student is answering the question correctly in three to ten seconds. A gray square means the student is answering that question incorrectly or is taking too long to answer that question. A white square means the student has not started practicing that fact. To see the specific question each cell refers to place the mouse cursor over the cell and a tooltip will pop up identifying the specific fact.
What does the progress graph mean on the student reports?
Progress Graph
The progress graph shows how the mastery score is changing over time. The color of the dot indicates how well the student did on the quiz that day. A green dot means less than 10% wrong. A yellow dot indicates 10-25% wrong. A red dot indicates over 25% wrong.
How does my child earn a score of 100?
In order for a child to get a mastery score of 100, students need to answer every question correctly two out of the last three attempts cumulatively over several recent sessions. Only questions on the quiz, which is the first two-minute activity of each day, count for this. The practices, which are repetitive, do not count toward the mastery score.
What does the yellow smiley, green check, blue hourglass and red X icons mean?
Progress Graph
Click on the colored dots on the student report calendar or the class report usage column to see detailed information about the questions answered by the student. A yellow smiley face means the.question was answered correctly within 3 seconds. A green check mark means the question was answered correctly within 10 seconds. A blue hourglass means the question was not answered within 10 seconds. A red X means the question was answered incorrectly.
How do I print the reports? Can I print the reports for all students at once?
Sign in to your account and print any report page using the print function of your browser. There is no PDF download or separate print version of report pages. For best results use an up-to-date browser and in the print dialog select the option to enable printing of background images. Unfortunately, there is no way to print all of the student reports at once.
My child's score is stuck in 90s. How can they finish the operation and move on?
This typically happens when students have an error rate that is too high. This can be confirmed by looking for yellow or red dots on the parent and teacher reports. A yellow dot indicates a student is getting more than 10% of the answers wrong. A red dot indicates the student is getting more than 25% of the answers wrong. Students that are regularly getting yellow and red dots should be reminded to type in answers as quickly as possible but not so quickly that they make mistakes. Also, they should not guess answers and never enter incorrect answers on purpose. If teachers or parents feel that the child's frustration is to the point of being counterproductive they can manually reassign the student to another operation as described elsewhere in this FAQ.

Teacher Accounts

How do I transfer students' accounts from last year into my new class this year?

You don't. Just follow the checklist for your new class, adding all students as new, and sending home parent flyers. When parents follow the instructions their child's previous accounts will be merged into your new class. XtraMath is designed to make it as easy as possible for teachers -- this process prevents you from having to collect and enter XtraMath account information from your students.

The only exception is if you are "looping" -- keeping the same class from one year to the next. In that case you can simply extend the expiration date of the class by a year. To change the expiration, click "Edit class info" in the left column of the class report. If your class has already expired and no longer appears in your teacher account contact us and we will restore the archived class.

Where do I find my classroom code?
To look up your classroom code sign in to your teacher account, click on the Account menu item at the top. Your classroom code is shown just above the green Update button. Classroom codes only show up for teacher accounts, not parent accounts.
How do I delete a student from my class?
In your teacher account click on the student's name to see the student report. On the student report click "Remove this student" in the left column.
How do I set up XtraMath to work in a computer lab?

Please see our article, "Computer Lab Setup for XtraMath".

How do I add a new student to an existing class?
In your teacher account click "Add students" in the left column. If you have multiple classes in your account, first click the tab for the correct class.
How do I transfer a student from one class to another?

Only transfer students that are switching classes in the middle of the school year or that were inadvertently added to the wrong class. For "transferring" students' accounts from last year's class to this year's class see the related question above.

This two-step procedure assumes that the classes belong to different teachers. To transfer students between classes in a single teacher account just use the same teacher account for both steps.

First, the receiving teacher can adds the student by clicking "Add students" in the left column of the class report. In the add student box, pick the "Transfer student..." option and enter the student's name, PIN and email address of originating teacher.

Second, the originating teacher can delete the student from their class. Click on the student's name in the class report to view the student report, then click "Remove student" in the left column of the student report.
How can I share my class with another teacher?

In your teacher account click on "Share this class" on the left side of the screen. You will then be able to enter in the email address of another teacher that has an XtraMath account. We will send them an email containing a link they can use to add this class to their account.

If you want to share only one or a few students then see the question immediately below.

How can I share an individual student with another teacher?

A single student can be shared between teachers. The second teacher can add the students needed by signing in to their teacher account and then clicking "add student". In the add student box, pick "transfer student" and enter in the student's name, PIN and email address of the teacher who is already linked. It will not remove the student account from the original teacher.

If you want to share an entire class with another teacher see the question immediately above.

XtraMath on Tablets and Phones

I thought XtraMath was free. Why are you charging for the apps?
For the first few years of our existence we relied on donations from parents and teachers. However, the donations were never sufficient to cover the costs of operating and improving XtraMath. Usage of our program has grown dramatically and operating on donations became unsustainable. Most online educational programs either display advertising or charge a subscription. We are firmly committed to not showing ads to children. By charging a few dollars for our mobile apps we can keep our website free of charge and free of advertising.
What is the difference between the free XtraMath website and a paid XtraMath app?

We do not want kids in families that can't afford smart phones and schools that can't afford tablets to have an inferior educational opportunity. Therefore, the essentials of the program function in the same way on the website as in an app on a tablet or smart phone. However, when you are on a smart phone or tablet the app does provide a better experience. The app can be launched directly from a home screen, there is no browser "chrome" taking up space on the screen, the screens have been formatted optimally for the smaller screen size, Given the modest price we feel that the apps provide good value.

(Also, Mr. C. videos do not work in the web version of XtraMath on iPads and iPhones. See the video-related question in the Technical Issues section for an explanation.)

Why are there separate apps for phones and tablets?
Because on a phone XtraMath works better in a portrait (tall) orientation and on a tablet XtraMath works better in a landscape (wide) orientation. For technical reasons we cannot combine those two into a single app. If it were possible for us to offer both apps for the price of one we would do it, but this is also not possible due to the way that the app stores function. If we can figure out a way to combine both into a single app or offer both apps for a single price we will do so.
Is there an educational discount for the apps?
We participate in the Apple Volume Purchase Program which gives a discount for volume purchases. Apple sets the terms of the discount and we do not have any control other than opting in.
Which Apple iPad, iPhone, and iPod Touch devices are supported?
Our iPad and iPhone apps run on iOS 7 or later, so any device that can be upgraded to iOS 7 is supported. This includes iPad 2 and later, iPhone 4 and later, and iPod Touch 5 and later.
What about Android, Kindle, Microsoft, etc. apps?
We are actively working on releasing apps for these other device platforms. If your child or students are using XtraMath then you will see an announcement appear in the weekly report email or in a separate announcement email.

Technical Issues

Mr. C. videos are unavailable. It says I need to install Flash.

Our website uses Adobe Flash to play the Mr. C. videos in the student activities. On a desktop or laptop computer you can simply install Flash.

Apple doesn't allow Flash on its iPads, iPods, and iPhones. To see the Mr. C. videos on those devices you will have to buy the app from the App Store. The Mr. C. videos only appear in the first few sessions, and then there won't be any until the student moves on to the next operation. If you don't wish to buy the app then have your child do XtraMath on a laptop or desktop computer until the Mr. C. videos stop appearing, then switch your child to the iPad or iPhone.

Why is there no sound with the videos of Mr. C. on my iPad?
The iPad has two audio controls on the side. One is for volume up and down. The other is a switch to turn the ringer on and off. For audio to play in our app the volume must be turned up and the ringer switch should be set to on position.
What are the minimum requirements to run XtraMath?
Shown below is the minimum version number for the most popular browsers. For best results, update your browser and flash player to the most recent version. Update your flash player on Adobe's Flash Player page. Javascript and browser cookies also need to be enabled. These are almost always enabled since many websites would break without them.
  • Internet Explorer 8
  • Safari 4.0
  • Chrome 4.0
  • Firefox 3.5
What IP addresses are used by XtraMath? is our main site. is a content distribution network that serves XtraMath images and other "static assets". simply redirects to

The IP addresses for these domains are controlled by Amazon Web Services and are subject to change. We do not have control over when or how these addresses may change.

IP addresses can be resolved with a service such as the KLOTH.NET DIG tool. To use the tool, enter the domain you wish to resolve(e.g., then click "Look it up". The IP addresses corresponding to the domain will be listed in the answer section of the output.

How do I get XtraMath to work with parental controls on the Mac?
Add the following domain names to your parental controls white list.
Your videos appear to be blocked by our district. How can I watch a video from your website?
The videos on our home page and in the "Learn More" section of our web site are hosted on Vimeo which is blocked by some districts. As an alternative, all of our videos are also available on TeacherTube.


I still have a question after reading this FAQ. How can I get help?
We can provide a limited amount of support via email. Go to our Support page for instructions.
Is XtraMath available in Spanish?
Not yet. However, parent flyers can be printed in Spanish. Look for the language selection at the top of the flyers page. Keep in mind, though, that parents will have to go through an English-only enrollment process, and receive confirmation emails and reports in English.
What are your terms of service?
Our terms of service are shown on our sign up page.
What is your privacy policy?
Here is our privacy policy. Basically, we keep your information private, only use your email address to send you information related to XtraMath, and you can opt out of email if you want.
What is XtraMath's tax ID number?
XtraMath is a 501(c)(3) charity. Donations to XtraMath are tax deductible. XtraMath's tax ID number (EIN) is 27-1042188.