An expression contains one or more terms or numbers, where each term or number is separated by an operator but an expression does not have an equals sign.

Use knowledge of balancing equations to solve problems

Maths

In this unit pupils will explain how to balance equations with addition or subtraction expressions and use their knowledge of balancing equations to solve problems. In the future unit pupils will compare and represent the structure of problems with two unknowns using a bar model. They will systematically solve problems with two unknowns using trial and improvement.

In the prior unit pupils explained how increasing or decreasing the minuend affected the difference. They used known facts to explain how adjusting the minuend made mental calculation easier. In this unit pupils will explain how to balance equations with addition or subtraction expressions and use their knowledge of balancing equations to solve problems.

Calculating using knowledge of equivalence in addition and subtraction

Which symbol needs to go between this pair of expressions?

What is the smallest possible value for the missing number in this equation?

What is the difference in rainfall between June and July in Sydney? Give your answer using the correct unit of measure.

Which of these statements represents comparing the wettest and driest months in Sydney and Manchester?

Use the correct inequality symbol to make this correct: 16.75 {{ }} 19.05

Which of the following expressions has the same difference as 10 − 5.5? Can you reason without calculating?

What is 5.35 when rounded to the nearest whole number?

Use an efficient strategy to calculate 45.85 + 29.96 = {{ }}

Use an efficient strategy to calculate 67,895 − 65,460 = {{ }}

Izzy begins with 800 g of plasticine and removes 75 g. Jun begins with 980 g of plasticine and removes an unknown amount. Now they have the same mass of plasticine. How much did Jun remove? {{ }} g

This lesson will soon be taken down.

Use knowledge of balancing equations to solve problems

Lesson outcome