Use properties of numbers and the commutative and associative laws to simplify calculations | Exit Quiz | Oak National A

Which factors would be best to associate together to calculate efficiently? 4 × 5 × 7 = ___

• 4 and 5

• 5 and 7

• 7 and 4

Answer explanation

Associating 4 and 5 together would produce 20, which can then be multiplied with 7 and would be equal to 140

Tick the three factor equations that would be equal to this two factor equation. 15 × 20 = ___ × ___ × ___

• 15 × 4 × 5

• 15 × 3 × 5

• 3 × 5 × 20

• 15 × 2 × 10

Answer explanation

Breaking down two factor equations into 3 factor equations can often make our calculations easier.

Tick the numbers that could be multiplied by a one digit number and would be equal to a multiple of 10.

• 8

• 9

• 12

• 15

Answer explanation

Knowing which numbers are equal to a multiple of 10 when multiplied by a single digit can be useful when looking to make calculations more simple.

Find the product of this equation.

(a)  

Answer explanation

You have managed to use your factors of 100 to help you find the product.

Match the 4 factor equations that are equal to the two factor equations.

• 4 × 11 × 3 × 5

• 21 × 12

• 2 × 6 × 3 × 7

• 18 × 24

• 3 × 6 × 4 × 6

• 16 × 15

• 4 × 4 × 3 × 5

• 33 × 20

Answer explanation

You have shown you can identify the factors of two, two digit numbers as a 4 factor equation.

Find the product of this equation. 32 × 15 = (a)  

Answer explanation

You have managed to use your knowledge of factors to solve this equation. Could you have solved it another way?