Goal: I can use known facts, doubles and near doubles strategies to help me subtract.

Listen to the audio below to have the lesson explained to you.

First, look at the examples below and sort them into known facts, doubles and near doubles.

4 + 4 = 8	6 + 4 = 10	7 + 8 = 15
		(7 + 7 = 14 Plus 1 = 15)

Next, use the equations below and figure out the answer using known facts, doubles and near double strategies.

10 – 9 =	14 – 7 =	19 – 9 =
10 – 3 =	16 – 8 =	15 – 7 =
10 – 6 =	18 – 9 =	7 – 3 =
10 – 5 =	6 – 3 =	9 – 4 =
10 – 2 =	8 – 4 =	5 – 2 =
10 – 4 =	4 – 2 =	13 – 6 =

Then,  think about using this strategy if the digits increase in place value. For example:

100 – 90 =	140 – 70 =	190 – 90 =
100 – 30 =	160 – 80 =	150 – 70 =
100 – 60 =	180 – 90 =	70 – 30 =
100 – 50 =	60 – 30 =	90 – 40 =
100 – 20 =	80 – 40 =	50 – 20 =
100 – 40 =	40 – 20 =	130 – 60 =

Finally,  set a timer for 3 minutes and practise your skip counting in you book going forward and backwards. Focus on the ones you know you need to work on.