Page 51 - ICSE Math 4

Multiplicationtion
5 Multiplica

Learning Outcomes

Students will be able to learn:
 to construct and write multiplication tables up to 10.
 to multiply 2-digit and 3-digit numbers using standard algorithm and lattice algorithm.
 to estimate the of products of two or more given numbers and their verifi cation.
 to solve word problems based on a mathematical statement.

We know that mul plica on refers to repeated addi on of the same number or a group
of things. We also know that if a number is mul plied by 0, the result is 0, and if a number
is mul plied by 1, the result is the number itself.

Constructing Tables

We have learnt how to construct mul plica on tables in diff erent ways such as repeated

addi on, skip coun ng and by adding 1 to 10. Let’s quickly revise them with the help of
following examples.
Example 1: Construct the table of 7 using repeated addi on.

Solu on: To construct the table of 7 using repeated addi on, we repeatedly add each
number (1 to 10) 7 mes.

1 + 1 + 1 + 1 + 1 + 1 + 1 = 7 or 7 ones are 7 or 7 × 1 = 7

2 + 2 + 2 + 2 + 2 + 2 + 2 = 14 or 7 twos are 14 or 7 × 2 = 14
3 + 3 + 3 + 3 + 3 + 3 + 3 = 21 or 7 threes are 21 or 7 × 3 = 21

4 + 4 + 4 + 4 + 4 + 4 + 4 = 28 or 7 fours are 28 or 7 × 4 = 28

5 + 5 + 5 + 5 + 5 + 5 + 5 = 35 or 7 fi ves are 35 or 7 × 5 = 35
6 + 6 + 6 + 6 + 6 + 6 + 6 = 42 or 7 sixes are 42 or 7 × 6 = 42

7 + 7 + 7 + 7 + 7 + 7 + 7 = 49 or 7 sevens are 49 or 7 × 7 = 49
8 + 8 + 8 + 8 + 8 + 8 + 8 = 56 or 7 eights are 56 or 7 × 8 = 56

9 + 9 + 9 + 9 + 9 + 9 + 9 = 63 or 7 nines are 63 or 7 × 9 = 63

10 + 10 + 10 + 10 + 10 + 10 + 10 = 70 or 7 tens are 70 or 7 × 10 = 70
Example 2: Construct the table of 8 by skip coun ng.

Solu on: 8 16 24 32 40 48 56 64 72 80

+8 +8 +8 +8 +8 +8 +8 +8 +8

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