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\ 12-Sep-2024 Surender Prajapati Proof-5 Reader’s Sign _______________________ Date __________

3. Find the product.
(a) 50 × 10 (b) 10 × 16 (c) 12 × 30

(d ) 20 × 60 (e) 124 × 10 (f) 8 × 100
4. Multiply.

(a) 20 × 700 (b) 500 × 16 (c) 900 × 9
(d) 200 × 19 (e) 31 × 300 (f) 17 × 100

properties of Multiplication

1. Order Property: Numbers can be multiplied in any
order and their product will remain the same. or

We observe that changing the order of two numbers 4 groups of 3 3 groups of 4
= 4 × 3 = 12 = 3 × 4 = 12
does not change the product.

Examples: (a) 8 × 4 = 32 = 4 × 8 (b) 125 × 10 = 1250 = 10 × 125

2. Property of 1: When a number is multiplied by 1, the product is the number itself.
Examples: (a) 7 × 1 = 7 (b) 53 × 1 = 53 (c) 124 × 1 = 124

3. Property of 0: When a number is multiplied by '0', the product is always '0'.

Examples: (a) 5 × 0 = 0 (b) 17 × 0 = 0 (c) 142 × 0 = 0

estiMating proDuct

To estimate the product, we first round off the multiplier and the multiplicand to the

nearest tens, hundreds or thousands and then multiply the rounded numbers.

Example: Find the estimated product: 73 × 26 th H t O
Solution: 73 rounded off to the nearest 10 is 70. 7 0

26 rounded off to the nearest 10 is 30. × 3 0
0 0
Now, 70 × 30 = 2100 + 2 1 0 0
Thus, the estimated product = 2100 2 1 0 0

practice time 4F

1. Fill in the blanks using the properties of multiplication.

(a) 11 × ____ = 11 (b) ____ × 1 = 28 (c) 15 × 6 = ____ × 15

(d) 25 × ____ = 39 × 25 (e) ____ × 29 = 0 (f) 175 × ____ = 0

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