An unknown is a quantity that has a set value but it is represented by a symbol or letter.

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

An expression contains one or more values, where each value is separated by an operator.

Explain how to balance equations with addition expressions

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

Use rounding, estimating, comparing or reasoning to determine the missing symbol in this inequality statement. 23 + 17 {{ }} 32 + 28

Use rounding, estimating, comparing or reasoning to determine the missing symbol in this inequality statement. 4.7 + 3.9 {{ }} 4.9 + 2.5

Use rounding, estimating, comparing or reasoning to determine the missing symbol in this inequality statement. 34,506 + 17,853 {{ }} 56,231 + 19,106

Complete the equation that is represented by the bar model. a + 6,214 = {{ }}

Balance the equation by finding the unknown value. d + 17.6 = 17.65 + 102   What is the value of d?

Balance the equation by finding the unknown value. 14.62 + 18.95 = f + 31.5   What is the value of f?

Which of the following expressions has the same sum as 132 + 16? Can you reason without calculating?

Which of the following expressions has the same difference as 200 − 90? Can you reason without calculating?

Round 14,703 to the nearest multiple of 10

Use the correct inequality symbol to make this correct: 234,076 {{ }} 78,835

What is 17.37 when rounded to the nearest whole number?

Use an efficient strategy to calculate 14,758 + 12,030 = {{ }}

Starter Quiz