## Let's learn!

**What is doubles minus 1?**

Doubles minus 1 is a strategy used to add two consecutive numbers that is, when they are next to each other.

We simply add the bigger number twice or double it and then, subtract 1 from it, to get the final result.

Here, for example, consecutive number 7 and 8 have been added using the doubles minus one strategy.

Here are more examples of the double minus 1 strategy.

## Let's sing!

*Let’s add consecutive soap bubbles,*

*Adding five and six; there’s no trouble!*

*Just make the bigger number double,*

*Subtract 1 from the double of bubbles.*

## Let's do it!

Have fun with your child by asking them to find the doubles of numbers you say and then use double minus 1 and doubles plus 1 strategies to find the sum of consecutive numbers between 1 and 20.