Background

1/20/10

Thinking About Numbers


We just survived a long unit in multiplication. The test showed that while they understand the actual act of multiplying, what it meant, etc... it also showed that they are having a hard time remembering the little facts - the multiplication facts that they have been learning for, oh, a few years now.

So we're doing a little backtracking. In order to prepare for division, we are making what the Investigation series calls "Multiplication Towers." Each pair of students gets a 2 digit number. I gave them a 300 chart to highlight all of the multiples of their given number. For some students, this meant they were only highlighting a few numbers on the chart. So, they were also asked to look for a pattern to help them continue the multiple pattern. Some students, such as the pair that was given the number 60, decided to instead highlight the multiples of 6 - knowing that they could add the "0" and create the multiple of 60.

Once they created a sufficient list, checked it, etc... I gave them a long strip of counting tape - "As tall as you are!" to create their multiplication tower. They start with the original number on the bottom, adding multiples above. My plan is to go over some observations of the towers, including what are multiples of 10 and 20 on their tower (without letting them count up!) Then, we will begin division discussions using the towers (thinking top down instead of bottom up). Here are some shots of my worker bees:






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