Page 39 - MathGPT_V1.0_C5
P. 39
D:\Surender Prajapati\Books Final_CBSE and ICSE\ICSE\Preparatory_Stage_Maths-5_(31-10-2023)\Open_Files\CHAP_02
\\November 3, 2023 10:57 AM Surender Prajapati Proof 5 Reader _________________________ Date: ___________________74
When a number is multiplied by 100, we put two zeros to the right side of the number.
Examples: (a) 643 × 100 = 64300 (b) 8572 × 100 = 857200
When a number is multiplied by 200, 300, 400, ..., 900, we multiply the number by 2, 3,
4, ..., 9 respectively and then put two zeros to the right side of the product so obtained.
Examples: (a) 78 × 400 = 31200 (b) 273 × 800 = 218400
When a number is multiplied by 1000, we put three zeros to the right side of the number.
Examples: (a) 15 × 1000 = 15000 (b) 198 × 1000 = 198000
When a number is multiplied by 2000, 3000, 4000, ..., 9000, we multiply the number
by 2, 3, 4, ..., 9 respectively and put three zeros to the right side of the product so
obtained.
Examples: (a) 24 × 3000 = 72000 (b) 571 × 7000 = 3997000
Multiplication of Large Numbers
Larger numbers are multiplied in the same way as smaller numbers. To multiply large
numbers, we follow the following steps.
Step 1: Write the numbers in column. The number that is to be multiplied
Step 2: Start multiplication from the ones place. is called the multiplicand.
The number by which we multiply
Step 3: Move to the tens place, is called the multiplier.
hundreds place and so on. The result of the multiplication is
Step 4: Add the carry over if any. called their product.
Example 1: Multiply the following.
(a) 6172 by 435 (b) 4567 by 2315
Solution:
(a) Step 1: Expand the multiplier.
435 = 400 + 30 + 5
Step 2: Multiply by the ones.
TL L TTh Th H T O
6172 × 5 = 30860 6 1 7 2
Step 3: Multiply by the tens. × 4 3 5 400 + 30 + 5
3 0 8 6 0 6172 × 5
6172 × 30 = 185160 1 8 5 1 6 0 6172 × 30
Step 4: Multiply by the hundreds. + 2 4 6 8 8 0 0 6172 × 400
2 6 8 4 8 2 0
6172 × 400 = 2468800
Step 5: Add all the partial products.
30860 + 185160 + 2468800 = 2684820
Thus, 6172 × 435 = 2684820
Mathematics-5 37

