An array is when items are arranged in rows and/or columns.

Factors are whole numbers which exactly divide another whole number.

The associative law states that it doesn't matter how you group or pair values (i.e. which we calculate first), the result is still the same. It applies for addition and multiplication.

Working efficiently means finding a way to solve a problem quickly whilst also maintaining accuracy.

Explain the reasons for changing two-factor multiplication calculations to three-factor calculations

Maths

In this unit pupils will explain the use of the commutative and associative laws when multiplying three or more numbers. In the future unit pupils will explain reasons for changing 2-factor multiplication calculations to 3-factor multiplications explaining what a factor is and how to use arrays and multiplication/division facts to find them. They will identify prime numbers and composite numbers.

 In the prior unit pupils explained volume using a range of contexts and described the units used to measure volume. They explained how to calculate the volume of a cuboid and explained what a cube number is. In this unit pupils will explain the use of the commutative and associative laws when multiplying three or more numbers.

Multiply 3 or more numbers (commutative and associative laws)

Which statement is correct about this array?

Tick all the statements or expressions that are true about the representation.

Tick the array that has been divided correctly into 3 factors.

Which pair of factors would you choose for this calculation to calculate most efficiently?

He could simplify it further by using 4 × 12

He could simplify it further by using 2 × 24

Andeep is calculating 5 × 48   He says he has simplified his calculation to 5 × 8 × 6 to make it easier.  Which statement is correct? 

What is the missing factor  7 × {{ }} = 84

Which pair of factors would you multiply together first to create the most efficient calculation? 17 × 40 × 5 =  

There are two rabbits and each rabbit eats 50 g of food a day. How much will the rabbits have eaten in total after 14 days? {{ }} g

There are 4 children in the family. They all drink a 250 ml carton of milk each at breakfast. How much milk is drunk in total each week? {{ }} ml

This lesson will soon be taken down.

Explain the reasons for changing two-factor multiplication calculations to three-factor calculations

Lesson outcome