1. Distributive law of multiplication

2. distributive law of multiplication
（40+10）× = 40× ×70
distributive law of multiplication
1)The sum of two numbers multiplied by another number.
2)We can multiply the two addends by the number respectively and then add two products.
3)The result remains the same.

3. Which one is easier to calculate?
63×29+29×37
（63+37）×29
16×9+4×9
（16+4）×9
125×（8-1）
125×8-125×1

4. 125×（8－1）=125×8－125×1
1)The sum/difference of two numbers multiplied by another number.
2)We can multiply the two numbers by another number respectively and then add/minus two products.
3)The result remains the same.

5. ● Distributive law of multiplication. （a + b）×c=a×c + b×c
1.Fill in the blanks by using the distributive law of multiplication.
(1)（93＋28）×11=93× ＋ ×28
(2) 20×（80－10）=20× －20×
(3) ◆ ×★—●×★=（ — ）× 11 11 80 10 ● ★ ◆

6. √ × × Distributive law of multiplication.
The sum/difference of two numbers multiplied by another number. We can multiply the two numbers by another number respectively and then add/minus two products. The result remains the same.
（a + b）×c=a×c + b×c
2 .Without calculating decide if the following are true or false and then explain the reason.
(Show them with “√”or“×”)
（a）（22－17）×35=22×35－22× （ ）
（b） 78×91＋91×25= 78＋25 × （ ）
（c） 8×（11×9）=8×11×8× （ ） √ × ×

7. A
（1）17×4+17×6
（2）63×34- 63×24

8. B
（1）（8+10）×125
（2） 99×12

9. C
（1）999×99+99

10. A boy wants to buy something in the supermarket.
Product name
unit price
quantity
chocolate
£12
11bags
biscuits £6
sweets £2
(1)How much is that altogether?
(2)How much more did he spend on chocolate than
on sweets?

11. When the boy was solving the number sentence: （□+50）×4 , he calculated it like this, □×4+50 What’s the difference between the wrong answer and the right answer? =
（□+50）×4
□×4+50×4
50 × 3
□×4+50