NZ Level 2
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Equivalent number sentences (add/sub)
Lesson

In mathematics, we talk about number sentences (called equations) that are equivalent. "Equivalent" means that one side of the number sentence is equal to the other side.

Since mathematics is a special language, we can show that one side of the equal is equal to the other using the equals sign, =.

For example, I could write $1+2=3$1+2=3. Since both sides of the equation are equal to $3$3, we can say that this is an equivalent number sentence. Watch this video now as we look at some more ways we can write equivalent number sentences.

Worked Examples

Question 1

Complete the number sentence: $27+\editable{}=52$27+=52.

ThinkIf we start at $27$27, how many do we need to count up by to reach $52$52. We can use a strategy (e.g. the jump strategy) to help us work this out.

Do: $27+25=52$27+25=52. The missing number is $25$25.

 

Question 2

Complete the number sentence:

  1. $119-\editable{}=46+47$119=46+47

Outcomes

NA2-8

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