Addition and Subtraction Facts to 20
 Why should I learn the facts?
Help children to volunteer answers, such as they will need to know the facts to add the score for games, to know how much to pay for two or more items, to make change, to find how many when two or more groups are combined, to find how many are left, how many more, how many fewer, and so on. You can also tell them that these facts are like the alphabet – they will need them later as they learn to do more complex math.
 If I learn one fact, will it help me to remember other facts?
Explain to children that once they learn a fact, they know the fact family. They can use doubles to find the answer for doubles plus one. Also explain that other strategies help them remember facts, e.g., zero doesn't change a number, one makes a number go up or down by 1.
 If I don't know a fact, what can I do?
Remind children that they can try to remember its related fact, or use one of the strategies they learned to figure out the answer.
 
