Sometimes counting circle reveals HUGE holes in a student’s thinking. Today it revealed quite a large black hole in almost all of my student’s thinking today. They had an EXTREMELY hard time counting up by 70 and after the entire counting circle was complete we asked them why it was so hard. The third picture has a small statement made in the top right corner. Why do they see 70 as a “hard” number to add? Their reasoning is because it is “so big” however we had to really struggle for them to see the connection between 2 sets of tens + 7 sets of ten =9 sets of ten (90) and 20 +70=90. They really did see it as two TOTALLY different problems. To cap it all off I had to ask the last three questions to make sure they saw the place value connection.