Transcript Distributive Property PowerPoint

The Distributive Property of
Multiplication
Grade 4 GLE 17
Recall the distributive property of
multiplication over addition . . .
symbolically:
a × (b + c) = a × b + a × c
and pictorially (rectangular array area model):
a
b
c
a×b
a×c
An example: 6 x 13
using your mental math skills . . .
symbolically:
6 × (10 + 3) = 6 × 10 + 6 × 3
and pictorially (rectangular array area model):
6
10
3
6 × 10
6×3
What about 12 x 23?
Mental math skills?
(10+2)(20+3) = 10×20 + 10×3 + 2×20 + 2×3
20
3
200
30
10
10 × 20
10 × 3
2
2 × 20
2×3
40
+ 6
276