## Wednesday, 11 March 2015

### MFM2P - Day 26 (finishing the test and starting V & SA)

Some of my students finished their test yesterday, but many didn't, so they continued today. Those who had finished worked on the warm ups from yesterday and today. We did this Estimation 180 as it ties in with what we will be doing for the next few days.

One of my students got it exactly right. He said that he thought the vase was about double the volume of the can. Not having done the previous Estimation 180s, he assumed the volume of the can was 355 ml, as is the case in Canada. In the US, the volume is 370 ml. It's ironic that had he known the actual volume of the can shown, he would not have gotten the correct volume of the vase.

Most got the rule, but some are still having trouble explaining how they got it. Here is what we did with it:

By this time only a couple of students were still working on their test (one was away yesterday) so we moved on to this handout.

Students were building rectangular prisms with linking cubes where the dimensions were randomly determined by rolling a die. They had to calculate volume and surface area.

Many students did not know how to build their prism once they had their dimensions. This reinforced the need to have them build. I circulated and helped them understand how to build their prism, what volume represented (number of cubes) and how to calculate it based on the dimensions of the prism. Some knew how to find surface area, but many did not know where to start but having the physical model in front of them made it really simple to explain it to them.

They will continue tomorrow and add cylinders and triangular prisms to the mix.

#### 1 comment:

1. I like the rolling of the dice idea for side lengths & then building w/ blocks to do SA & V of prisms. Nice!