Page 51 - Math Genius C4

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\\September 30, 2025 9:38 AM Bharat Arora P-9 Reader _________________________ Date: ___________________74

Mind Map
math Creative Thinking
AdditiON ANd SubtrACtiON

Addition of greater Numbers Subtraction of greater Numbers

Addition of greater numbers without regrouping Subtraction of greater numbers without regrouping
tth th H T O
tth th H T O 7 9 8 9 5 Minuend
3 2 4 7 5 Addend 1 – 3 6 7 4 3 Subtrahend
+ 2 4 3 1 2 Addend 2 4 3 1 5 2 Difference
5 6 7 8 7 Sum 5 ones – 3 ones = 2 ones
9 tens – 4 tens = 5 tens
8 hundreds – 7 hundreds = 1 hundred
Addition of greater numbers with regrouping
9 thousands – 6 thousands = 3 thousands
L tth th H T O 7 ten thousands – 3 ten thousands
= 4 ten thousands
1 1 1 1
Subtraction of greater numbers with regrouping
8 7 1 9 9 9 L tth th H T O
+ 1 9 9 9 9 14 12 15
8 9 1 9 9 8 6 4 2 5 12
4 7 5 3 6 2
– 2 2 9 7 6 4
Properties of Addition 2 4 5 5 9 8

1. Order property:
E.g., 21,425 + 32,147 = 32,147 + 21,425
2. grouping property: Properties of Subtraction
E.g., 2,150 + (32,140 + 54,789) = (2,150 + 32,140) + 54,789 1. 1 subtracted from any number gives its
3. Adding 1: E.g., 87,540 + 1 = 87,541 predecessor.
4. Adding 0: E.g., 67,532 + 0 = 67,532 E.g., 32,541 – 1 = 32,540
2. Zero subtracted from any number gives the
number itself.
E.g., 90,531 – 0 = 90,531
estimating Sum and difference 3. A number subtracted from itself gives zero.
E.g., 59,531 – 59,531 = 0
example: Estimating the sum of 25,138 and 63,848

Estimated Sum Actual Sum
tth th H T O tth th H T O
3 0 0 0 0 2 5 1 3 8 Addition and Subtraction together
+ 6 0 0 0 0 + 6 3 8 4 8
9 0 0 0 0 8 8 9 8 6 example: 1,55,423 + 15,067 – 37,643.

example: Estimating the difference of 11,782 and 38,741 L tth th H T O L tth th H T O
1 1 9
Estimated Difference Actual Difference 1 5 5 4 2 3 6 10 14 8 10
tth th H T O tth th H T O + 1 5 0 6 7 Sum 1 7 0 4 9 0
4 0 0 0 0 16 13 1 7 0 4 9 0 – 3 7 6 4 3
– 1 0 0 0 0 7 6 3 11 Add the numbers 1 3 2 8 4 7
3 0 0 0 0 3 8 7 4 1 having + sign Subtract the number
– 1 1 7 8 2 having – sign from the
2 6 9 5 9 sum obtained.

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