9-18-06

“Today we are going to think about things that come in groups: a group of things that are all the same. On one hand, how many fingers do we have? Show me with your fingers.” Some may answer 10, so repeat the question. “So that’s //one group// of //5 fingers//.”

Show a picture of a bicycle, or draw one on the board. “Here is 1 bicycle. How many wheels does it have? Show me on your fingers. Right, so this bicycle has //one group// of //2 wheels//.” Repeat with a tricycle.

“Who can think of other things that come in groups?”

My kids only thought of body parts, which mostly come in 2s. I wanted something that came in larger groups also, so my assistant teacher asked them to think about pets they had at their houses and their body parts. We talked about cats, who have 4 legs.

Draw two cats on the board (or whatever else they come up with that has about 4 in its group. It’s important to go with their own stories or ideas).

“Imagine we are taking Derek’s 2 cats to the vet to get their claws cut (their fingernails cut). Oooh, they do //not// like to get their nails cut! Who wants to be the vet?” One child comes up to the board to be the vet.

“Alright, Tyrone is going to be the vet and cut the cats’ nails. Go ahead, Tyrone. When you cut one, circle it on the board.” After he circles 3, stop him. “Ok, so how many feet did Tyrone cut? How many more does he still need to cut?” After that, repeat those questions after each additional foot, so you go through the list of how many he did and how many more he needs to do. This is their introduction to decomposing numbers.

Then, children go off to do Staircases, as described in //Investigations//, or Double Compare. Some children may need to play single Compare as well.

Ideas for practice for decomposing numbers: Using fingers, show different ways to make smaller numbers (under 5) How Many of Each? problems Snap It! Paper Clip Combinations (do all the ways to make one number one day, etc.) Build it in 2 Parts (see above) Tens Go Fish (or similar games) Number Sandwiches (53) I Wish I Had (51) Counters in a Cup Missing Part Cards 5 and 10 frames