Number & the laws of arithmetic

Which statement is always true?

1. A108 × 6 = 6 × 108
2. B108 − 6 = 6 − 108
3. C108 ÷ 6 = 6 ÷ 108
4. DAll of these

The commutative law says you can…

1. Aswap the order of the numbers when adding or multiplying
2. Bswap the order when subtracting
3. Cnever change the order
4. Donly swap the order for division

Which is an easier way to work out 25 × 9 × 4 (using the associative law)?

1. A25 × 4 × 9 = 100 × 9
2. BYou cannot change the order
3. C25 × 9 first, then × 4
4. D9 × 4 × 25 only

Using the distributive law, 36 × 8 is the same as…

1. A(30 × 8) + (6 × 8)
2. B30 × 8
3. C36 + 8
4. D(36 × 4) × 2

Which operation is NOT commutative?

1. Asubtraction
2. Baddition
3. Cmultiplication
4. Dnone of them

Which calculation shows the commutative law?

1. A34 × 16 = 16 × 34
2. B34 × 16 = 30 × 16 + 4 × 16
3. C34 + 16 − 16
4. D34 ÷ 16

Addition is commutative: 7 + 38 = 38 + 7.

Division is commutative, so 18 ÷ 6 = 6 ÷ 18.

For these numbers, 13 × 26 = 26 × 13.

For these numbers, 67 + 69 = 69 + 67.

For these numbers, 65 × 36 = 36 × 65.

For these numbers, 94 × 49 = 49 × 94.

For these numbers, 46 − 22 = 22 − 46.

For these numbers, 43 − 21 = 21 − 43.

For these numbers, 96 × 94 = 94 × 96.

For these numbers, 17 − 61 = 61 − 17.

For these numbers, 40 + 65 = 65 + 40.

For these numbers, 23 × 11 = 11 × 23.

For these numbers, 72 × 20 = 20 × 72.

For these numbers, 86 ÷ 39 = 39 ÷ 86.