Quantitative Aptitude - SPLessons

Maths Addition Tricks | Simplification

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5 Steps - 3 Clicks

Maths Addition Tricks | Simplification

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Addition Tricks – Calculation by Simplifying Numbers Principle of Equivalency

Example 1:
24 + 39


= (25 + 1) + (40 -1)


= 25 + 40


= 65


Example 2:
198 + 202

= (200 – 2) + (200 + 2)

= 200 + 200

= 400


Example 3:
414 + 596

= (410 + 4) = (600 -4)

= 410 + 600

= 1010


Example 4:
64 × 25

= (\(\frac{64}{4}\)) × (25 × 4)

= 16 × 100

= 1600


Here the terms are divided and multiplied by ‘4’ to simplify calculation.


Solve:
1. 79 + 86


= (80 – 1) + (85 + 1)


= 80 + 85


= 165


2. 989 + 951


= (990 – 1) + (950 – 1)


= 990 + 950


= 1940


3. 1549 + 1701


= (1550 – 1) + (1700 + 1)


= 1550 + 1700


= 3250


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Addition Tricks – Addition of Similar Digit Numbers:


Commonly asked question in Competitive exams 7 + 77 + 777 = ? Answer: 7 * 123 = 861


The result of this particular problem 8 + 88 + 888 = 984


How can we quickly add these numbers? What is the shortcut/trick?

1. 8 is the common number in this sum so we take 8 and replace it with 1 so the sum now becomes 1 + 11 + 111.

2. Now count the number of digits in each number i.e. 1 = 1 digit, 11 = 2 digits, 111 = 3 digits and so on.

3. Write down all the digits together, in this case, it would be 123.

4. Now take the original common number 8 and multiply it by 123 = 984.

Example 1:
9 + 99 = 9(12) = 108

9 + 99 + 999 = 9(123) = 1107

9 + 99 + 999 + 9999 = 9(1234) = 11106


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