5 Tips For Doing Math Quickly In Your Head

5 Tips For Doing Math Quickly In Your Head

Math is one of those subjects in school that is notoriously unpopular among students. Many students find themselves struggling with Math or numbers in general. Only a handful of exceptional students actually enjoy learning and solving equations.

No matter how difficult Math is, it cannot be denied that it is necessary for day-to-day living. To be able to participate in transactions and handle basic finance like budgeting and saving money, all of us need to have a strong understanding of basic math.

Tips To Perform Math Equations Mentally

If you’re struggling with mathematical equations, there are shortcuts that you can learn quickly. What many students don’t understand is that Math can be mastered only through constant practice and application in real-life situations. Since most methods are just simplified versions of another, then there are always ways to find a trick or shortcut to come up with answers faster.

For example, understanding the power of 10 may look complicated at first. However, the trick here is to simply understand that using the power of 10 is just the same as multiplying and dividing numbers by 10s. The power of 10 is simply a way to express huge numbers in short form. Remember, 10[1] simply means ten, while 10[2] is equal to 100, and so forth.

Aside from shortcuts, here are some useful tips for doing math problems in your head:

  1. Mental Math Tricks For Adding The Number Nine

To add nine to any number, add ten first, then remove one. For instance, you may simplify the addition 9 + 7 by changing it to 10 + 6, which is considerably easier to solve.

How would you mentally add 39 + 28? Change 39 to 40 and reduce 28 to 27. Now, the addition is 40 + 27. Another way to think about it is through compensation: 39 is one less than 40, and 28 is two less than 30. As a result, their total is three less than 70.

  • Mental Math Tricks For Addition

You can also add huge numbers mentally. For example, let’s add 9888 and 1234. The rule is easy to understand. Starting with the left side, add the digits one at a time (imagine the remainder one you need to add up).


+  1234


(9+1=becomes 11)

(8+2=becomes 11)

(8+3=becomes 12)

(8+4= becomes 12)

When you mentally write down the answer it becomes = 11122

In left-to-right addition, you’ve to recall smaller numbers than in right-to-left addition. Not only will you start calling out the answer from the very first step, but you also say it aloud as soon as you take your first step.

  • Subtraction By Addition

Subtracting through addition seems counterproductive, but this actually works—and you can do it mentally! This technique will help you subtract numbers in your head more easily.  For example, to find 8 – 2, consider “What number adds to two to produce eight?” In other words, you have to think of this equation instead: 2 + __ = 8

This is an important concept for many subtraction problems, particularly when the minuend is between 10 and 20. But it may be used in other digits like if you add 52 and 11, you get 63, hence the solution to 63-52 is 11.

  • Multiplication By Parts

This tip would be particularly helpful if you’re joining a mathematics quiz bee! To multiply huge numbers in your head, you can do so by multiplying the values individually and then adding everything to come up with the answer.

For example, it’s possible to arrive at the answer for 3 × 84 by multiplying 3 × 80 and 3 × 4 and then adding the results. That would be 3 x 80 = 240 and 3 x 4 = 12. Then, when added together, 240+12, the final answer is 252.

Another example would be 6 × 218. To multiply that by parts, you’ll get 6 × 200 = 1,200, 6 × 10 = 60, and 6 × 8 = 48.  When added together, the answer is 1308. As you see, you don’t need to memorize the multiplication table to know how to multiply large numbers.

  • Multiplication By 10 And 11

Again, you don’t have to memorize the multiplication table to solve huge numbers in your head. This trick is easy as pie. Multiplying any number by 10 is as simple as adding a zero at the end. For example, 88 multiplied by 10 gives 880. And if you’re multiplying a number by 100s or 1,000s, you just have to add another zero to the other number. For example, if the equation is 88 x 100, then just place two zeros to the number 88. Basically, the answer is 8,800.

Young Asian boy writing mathematical and physic formula onto a clear glass. Selected focus

There’s also a way to multiply numbers by 11 mentally. For example, let’s take 11 x 88. First, put a space between the digits of the other number. This number is 88, so it must look like this: 8_8. Then, add the two numbers together and place the total in the middle. It must look like this:



Then, add the first two digits together but retain the rest of the remaining digits in your answer. In this example, you must turn 8_16_8 into (8+1) _6_8. Naturally, you’ll get 968. Hence, the answer to 11 x 88 would be 968.

Keep Practicing

Knowing these techniques will let you do quick Math in any situation—even without a calculator! With constant practice, you’ll see that you can do mental math as easily as ABC. Remember, the key to mathematical mastery is constant practice and application. You must apply equations in real life to keep your arithmetic skills sharp.

Studying and practicing math equations may seem daunting, but it can be fun with the use of the right methods. If mental math is still too complicated for you, you can try honing your basic math skills through fun educational games that you can play during your pastime. And whenever you’re ready, you can start practicing mental math tricks in your head!

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About the Author: Leah Harper

Leah Harper is the global technology editor for Daily Mid Time, based in San Francisco. In past lives, he was editor at large for Time magazine, founder and editor of Technologizer, and editor of PC World. He writes about topics ranging from new products and services from tech giants to the startup economy to how artificial intelligence and other breakthroughs are changing life at work, home, and beyond.