Page 13 - E book 5

Delta Modern Language Schools

Primary stage Grade 5

Math department

1st term 2024/2025

Unit (3): Multiplication with whole numbers

Remark: All powers of 10 are multiples of 10, but not all the
multiple of 10 are powers of 10.

Ex: 60 is a multiple of 10, but not power of 10.

Strategies of multiplication:

1) Area model:

Example: solve using area model 629 x 34

x 600 20 9

30 18000 600 270

4 2400 80 36

So, 629 x 34 = 18000 + 2400 + 600 + 80 + 270 + 36 = 21 386

2) Distributive property:

Example: solve using Distributive property 62 x 354

*Break apart 62 into 60 + 2

*Break apart 354 into 300 + 50 + 4

(60 + 2) x (300 + 50 + 4) = (60 x 300) + (60 x 50) + (60 x 4)
+ (2 x 300) + (2 x 50) + (2 x 4)

= 18 000 + 3 000 + 240 + 600 + 100 + 8 = 21 948

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