Equivalent number sentences (add/sub)

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.

Think: If 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