Counting On in Math: Definition & Strategy

Instructor: Shannon Orr
Because mental math is a very useful life skill, there are many different concepts. This lesson is designed to define what counting on means. It will also give strategies for helping students understand and have the ability to use counting on in addition.

Retrain Your Thinking

When you learn to read, you are taught to start at the beginning of the sentence. When you learn to write, you are taught to start at the beginning of the paper. No surprise that when you are taught how to count, you are told to start at the beginning. There are songs, poems, and pictures that clearly show that counting always starts at the number 1. Now imagine first grade students walking into their classroom, sitting at their desk, and you, the teacher, announcing that they will begin counting from another number. Another number? This can't be real. Can't you just picture the terror on the faces of the little people looking back at you?

As an adult, the idea of counting on may seem pretty clear but to a child who has always started at the number 1, this idea may seem ridiculous and unbearable. Counting on is a mental math skill where, when adding two numbers, you begin counting from the largest number and add the second number to it. Counting on helps us figure out how many more we need of something and how many we will have once more is added.


Being able to count starting at any number is important for two main reasons. One reason is that it shows how well a student understands numerical order. For example, when students use rote counting or counting in order, teachers can't really determine how well they understand number order. Every day, Sally may be able to count from 1 to 20 without ever skipping a number. It may appear that Sally understands what number comes first, next, and so on until she reaches 20. The real test comes when the teacher asks Sally to start at number 7 and count to 20. If Sally only knows her numbers starting at 1, she hasn't truly grasped numerical order.

Another reason counting on is important is because it is the beginning steps for teaching students how to add. If Tony understands that after the number 11 there is 12, 13, 14, and so on, he has the foundation to be able to compute 11 + 3 = 14. Until students understand the numerical order, they may have a difficult time understanding how to add.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account