5th graders came down for their weekly visit. They had been working on decimals with their regular classroom teacher so we tried a Row Game–with strategically selected problems and answers. This pair was convinced that they had both done their work correctly, but dumbfounded how they had different answers (103.1 and 103.10). The group across the table reminded them about the “imaginary zeros after the 1.” GREAT conversations followed about those “imaginary” zeros, “invisible” decimal points and why we sometimes write them and sometimes don’t.
Number Talks today. I was pleased how many students had great mental math strategies to share and how many others were picking up on them and trying them out for themselves. Most students were “breaking apart” their numbers to make the multiplication simpler–like the right side of the pic. Only one student admitted to lining up the numbers and doing the algorithm in his head–or actually on his leg with his finger. After analyzing the two students’ work, I asked if maybe BOTH had broken their 12 apart to multiply it by 35.
Let’s just say we’ll be talking more about multiplication next week….