In this post we will try to understand addition tricks for fast math calculation. Mental Math is important not only for examination purpose but also for practical life.
Imagine you have to visit a grocery store where have to take your change back after the purchase, If you know how to do mental math the job get easy for you.
Now without wasting any time, let’s get started.
For adding number fast the best way is to make the number add with 10 or multiple of 10
5 + 10 = 15
110 + 10 = 120
110 + 100 = 210
605 + 10 = 615
See how easy it is to add numbers with multiple of 10.
So in order for mental math trick to work, to to convert the number into multiple of 10
for example
1. 117 + 11
Let see how we can add this number fast
a. First convert any number into multiple of 10
117 + 10 + 1
Here we written 11 in the form of multiple of 10
b. Now add accordingly (117 + 10) + 1
=> 127 + 1
=> 128
you can see how easy it is to perform this calculation mentally.
I hope the example is clear, now let us study different example for our practice.
2. 125 + 109
a. We will convert 109 into multiple of 100
=> 125 + 100 +9
b. Then we will do addition involving 100
==> (125 + 100) + 9
==> 225 + 9
==> 234
3. 117 + 99
a. first we will convert 99 to the multiple of 100
==> 117 + 100 -1
b. perform calculation involving 100 first
==> (117 + 100) – 1
==> 217 -1
==> 216
4. 135 + 365
a. First convert 365 into multiple of 100 and 10
135 + 300 + 60 + 5
b. Now add systematically
==> (135 + 300) + 60 + 5
==> (435 + 60) + 5
==> 495 +5
==> 5
5. 2132 + 3649
a. First convert 3649 into multiple of 1000, 100 and 10
2132 + 3000 + 600 + 40 + 9
b. Now add systematically
==> (2132 + 3000) + 600 + 40 +9
==> (5132 + 600) + 40 + 9
==> 5732 + 40 + 9
==> 5772 + 9
==> 5781
