which basic multiplication fact can you use to find the product of 40 and 30

Question

It's for my math i get stuck a lot please help!?

Answer 1

30 x 40 = 120

30= 3 x 10

40 = 4 x10

3 x10 x 4 x 10

= 3x4 x 10x10

= 12 x 100

=1200

basic fact is from your multiplication tables, which you have to memorize. Until then use a calculator.

3x4 = 12

1 2 3 4 5 6 7 8 9 10 11 12

2 4 6 8 10 12 14 16 18 20 22 24

3 6 9 12 15 18 21 24 27 30 33 36

4 8 12 16 20 24 28 32 36 40 44 48

5 10 15 20 25 30 35 40 45 50 55 60

6 12 18 24 30 36 42 48 54 60 66 72

7 14 21 28 35 42 49 56 63 70 77 84

8 16 24 32 40 48 56 64 72 80 88 96

9 18 27 36 45 54 63 72 81 90 99 108

10 20 30 40 50 60 70 80 90 100 110 120

4th column third row or 3rd column 4th row

4x3 = 12 or 3x4 = 12

and

10th column 10th row

10x10 = 100

30 x 40 = 3 x 10^1 x 4 x 10^1 = 3x4 x 10^(1+1) = 3x4 x 10^2

= 12 x 10^2

= 1200

= 1.2 x 10^3 in scientific notation