Mental Math and How It's Used

How this kind of math benefits school-aged children

Girl doing homework
Tim Robberts/The Image Bank/Getty Images

Simply put, mental math refers to the practice of doing calculations mentally or all in your head. Mental math is an extremely common and practical skill. Most people do at least some mental math on a daily basis. For example, we might mentally add the cost of two items to determine the total amount we owe. Or we might mentally subtract the number of minutes we have already spent on the treadmill from our total goal to determine how much longer we will need to run.

Mental math is a basic tool for school-aged children. Without the ability to do mental math, it can be difficult to complete ordinary daily tasks.

What Makes Mental Math Unique

Students who practice mental math make calculations in their minds without the guidance of pencil and paper, calculators, or other aids. Mental math is often used as a way to calculate an estimate quickly, using math facts that a student has committed to memory, such as multiplication, division, or doubles facts.

Why Mental Math Is a Good Life Skill

Mental math will not only serve students well in school, it'll help them outside of the classroom as well. Students who master the technique of mental math will find that the strategy helps them in many situations. They may use mental math when they visit the corner store and need to tally how much the bag of potato chips or candy bar they grabbed from the shelves will cost before they walk up to the register.

For teenagers and adults, mental math skills make it possible to calculate the price of sale items, know how big of a tip to leave, or how to split a bill when a large party dines out.

Telling students the practical ways mental math can help them will likely motivate them to become more skillful at the practice.

Studies have shown that students are more interested in learning techniques that they can apply to real-world situations.

When Students Struggle With Mental Math

Certain students will be better at some forms of mental math than others. Some students may be able to easily add and subtract but may face difficulty dividing and multiply mentally, especially when large numbers are involved.

If your child struggles with all forms of mental math, it's important to discover the root of the problem. Does your child struggle in math class, even when pencil, paper, and calculator are handy? Or does your child struggle only to calculate figures in his or her head?

Difficulty completing mental math problems may signal that your child hasn't mastered basic mathematical strategies. Talk to your child's teacher to see if she thinks that a learning disorder, such as dyscalculia, may be at play. The teacher can review portfolios of your child's work and assessments to decide whether she thinks a learning disability is a possibility.

On the other hand, perhaps your child just needs more practice at mental math. Parents can encourage children to put their mental math skills to use by playing mental math games at the grocery store.

Have your child tally up the cost of some of the items in the cart in his head or have her figure out how much a box of fruit snacks will cost if they're on sale at a 10 percent discount. Remember not to pressure your child and to make these activities fun and entertaining. 

Practicing mental math in the real world may be just what your child needs to perfect the skill.