math

Non-standard units

After some interesting discussion about thermometers, we measured the temperature of hot water, snow and the classroom air. We had time to jump into some measuring of length, etc.

We’ve been measuring the length of things with rulers all year. But this was the first time I asked the class to use non-standard units. I put different kinds of math manipulatives out, and said, “You’ve been sitting here a while. Why don’t you go use the tools I put out to measure your tables.”

Some groups decided this meant they were to measure the perimeter of the table. Others measured the distance across.

I was surprised when these students used different units (blocks) but didn’t think it was a problem. (they are in grade 3.)And these grade 3s saw nothing wrong with spreading the blocks out. And the kids with the snap cubes counted every single cube by 1s (181 cubes total.)

This was a good assessment in that it showed me where my students are in their understanding of measurement. They all know how to use a ruler, but clearly they still have things to learn about measuring.