Set 09 Addition & Subtraction to 20

Recall of addition and subtraction facts come through use and practice. Students use known facts like doubles and teens to strategise unknown facts on the way to instant recall.

1. Just Doubles: Making a double, focuses students on using knowledge they have instead of counting to recall an unknown fact.
2. Play the Double: Using doubles knowledge the game focuses students on the inverse relationship between addition and subtraction.
3. No Counting Allowed:  As the title says, no counting, using 10+ or doubles to solve the missing addend. Extending the use of +/- 1 to +/- 2.  
4. 20 Addition: Using facts to 10, doubles and 10+ knowledge to build facts to 20.