The students in my class recently completed a mathematics test to allow me to find learning gaps in the use of the strategies that they use for answering addition questions. One of the glaring gaps was the ability to complete simple addition questions quickly. For instance, Peter was asked the question, 8+7+2=?, out came the fingers, used for counting on. We timed how long he took to get the right answer, seven seconds. The strategy now shared with him and the rest of the class was to look for numbers in the question that add to ten. So 8+2=10, then 10+7=17. With the strategy modeled for students, we moved on to further practise. Peter was asked, 3+9+7=, he was able find two numbers that added to ten, and quickly added the nine. He got the right answer in two seconds. Was this a fluke? No it wasn’t, I quickly fired more questions at him, same quick response. You see I said, 10 is a magic number.