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

An equation is used to show that one number, calculation or expression is equal to another.

Brackets are symbols used in pairs to group things together.

The order of operations is a set of rules that tell you which operations have priority over others in an equation.

Combine multiplication with addition and subtraction

Maths

In this unit pupils will explain how addition and subtraction can help to solve multiplication and division problems efficiently. They will learn how the distributive law applies to division expressions with a common divisor and using the distributive law to solve equations. In the future unit pupils will use priority of operations with positive and integers and decimals.

In the prior unit pupils explained the use of the commutative and associative laws when multiplying 3 or more numbers. In this unit pupils will explain how addition and subtraction can help solve multiplication and division problems. They will learn how the distributive law applies to division expressions with a common divisor and use their knowledge of the distributive law to solve equations. 

Order of operations

Multiplication has priority over addition and subtraction.

Any part of an equation that is in brackets should be completed first.

Think about the order of operations. Which of these sentences are correct?

Which bar model could you use as a representation to help solve this problem? Jun has 3 packs of 20 balloons. Sam has 4 packs of 12 balloons. Who has more balloons, and by how many?

Look at this problem. I have two packs of 25 stickers. You have three packs of 12 stickers. How many more stickers do I have? Which equation could you use to solve this?

Use the equation to help solve this problem. A class is organised into five teams of three children and four teams of four children. There are {{ }} children in the class. 

Match each equation to the correct solution.

Sam’s book has 120 pages. She reads 9 pages each day for 11 days. How many more pages does she have left to read? {{ }} pages.

An equation is used to show that one number, calculation or expression is {{ }} to another.

Look at the bar model. Which of these expressions could it represent?

Match the equations to the correct solutions.

Match the expressions that are equal in value. 

Aisha and Jun want to find the total number of cakes. Aisha calculates 8 + 8 + 8 + 8 + 8 + 8 and Jun calculates 6 x 8  They find the correct number of cakes. Whose method was more efficient? 

This lesson will soon be taken down.

Combine multiplication with addition and subtraction

Lesson outcome