## Friday, May 12, 2017

### Sampling in Math Class

Along with math books, we will continue our unit on probability, data collection, and sampling until the end of the year. (I'm saddened to think that there are only a few more math classes until we are out for the summer, and will pack in as much math fun as possible!)

On Monday, I read a letter to the children that the president of Cheerios wrote us. Ms. Oats asked for our in figuring out if putting toys in cereal boxes is a good idea - from a business and consumer point of view. She wants to think of toys that children will want to collect - six different toys that somehow work together or would be best as a set. That way, kids will want their parents to keep buying Cheerios until they have all six different toys. Ms. Oats doesn't know if this will be a good plan, as she knows that it will cost more to put toys in the boxes.

So we promised to help by doing a sampling. Each student (9 in all) did 4 different trials, using a six sided die. That way, we have a relatively large sample of 36 families. Each child rolled a die and marked their sheets (see example). Some families got really lucky - the child rolled a 1, 2, 3, 4, 5, and a 6, with no repeats, meaning that they had to buy the very lowest amount possible - 6 different toys in 6 boxes. Other families were not so lucky - the unluckiest families had to purchase 20, 30, or even more boxes, until they got all six different toys. Our most unlucky family had to purchase 33 boxes before they got all 6 toys.

This project took all week, because a lot of math was involved, and a fair amount of teamwork and discussion.

Here are groups of children figuring out all sorts of math - how many families were in their group, and how many boxes of cereal their families their families had to purchase altogether.

Today, each child put their mathematical and creative thinking in writing. They wrote back to Ms. Oats and told her about our research, giving her some facts and figures. They also gave their opinion on if they thought it was a good idea (all seem to think yes), and what they thought would be a good choice of toy. (If any cereal marketing people are reading this blog, key chains and Lego pieces seem to be popular choices with this set of 2nd graders.)