Addition can be a simple skill to learn. It is one of the first things that we learn as a child in school in Maths. But, growing up, it is important to learn how to do these calculations quicker in your head. In this post, we will give you two very simple techniques to speed up your mental addition calculations.
Split & Add
Suppose you have to calculate 27 + 25.
You can split 27 & 25 as 20 + 20 first, which is 40. We split it as 20 + 20 because it is easy to work with 20.
Then add the remaining 7 + 5 = 12.
So the final answer is 40 + 12 = 52.
Another way of adding the above two numbers 27 & 25 is to split it as 25,25,2.
25 + 25 + 2 = 52.
Splitting as 25,25,2 can be faster than 20,20,7,5.
You just need to split the question into numbers that you are comfortable with and are the closest to your question numbers.
Now, let us try with some bigger Numbers
Suppose we need to add 352 + 243
We can split it as 350,240, 2, 3.
350 + 240 can be quickly performed as it contains 0 at the end.
So, 350 + 240 = 590 (You may also split this as 300,200,50,40 for easier calculation)
2 + 3 is easy as well.
2 + 3 = 5
Now add both 590 + 5 = 595
There are no fixed rules for splitting the numbers. You should divide the numbers at your convenience.
You can apply this split & add method to more significant numbers as well. However, after a point, say beyond 5 to 6-digit numbers, you may find it difficult to split and calculate. So, if splitting seems to be complicated, we recommend adding the numbers digit by digit from right to left and forwarding the sums as they teach in primary schools.
Add using Subtraction
Suppose you need to add 158 + 93.
Now, since 93 is just 7 less than 100, you can simply add 100 to 158 first then deduct 7 from the sum.
158 + 100 – 7 = 258 – 7 = 251
Thus, 158 + 93 = 251.
So you can use this technique when one of the numbers is close to multiples of 10, 100, 1000, 100000 and so on.
Let us see one more example,
Suppose we need to add 437 + 283.
Now, 283 is just 17 less than 300. So we will first add 300 then deduct 17.
437 + 300 – 17 = 737 – 17 = 720.
When numbers are close to the end of 10s, 100s, 1000s and so on, it is easier to deduct the remainder later than splitting and adding.
Test your Addition Skills with Meritstore!
Did you understand the above techniques? Now it is the time to test yourself. How good are you at performing mental additions? To know test yourself on Meritstore for free right now!
Start now: Addition Exercise – Online Practice