Figure out how many different outfits you can have!
Supplies: three t-shirts, three pairs of pants, a few pairs of shoes. What to do: 1) starting with three t-shirts and two pairs of pants (or two t-shirts and two pairs of pants if your child is young), ask your child how many different outfits they can make. See if you can encourage them to count in a systematic way. 2) repeat with three t-shirts and three pairs of pants. 3) depending on how things went, you can add more t-shirts or more pants or add shoes. Be careful though, adding two pairs of shoes will double the numbers in steps 1) and 2) so numbers get large very fast.
Bel and Nia together found 34 Easter eggs. Bel found 2 more than Nia. How many did Bel found?
HINT: if you can’t solve it with 34 – try an easier problem. What if they found 10 eggs together (and Bel still found 2 more than Nia)? Mathematicians do this all the time: they start with small numbers and try different easier problems until they get the hang of the problem.
How it went
We had a pile a laundry – which was the inspiration for this activity.
I started with 2 shirts and 2 pairs of pants. Bel and Nia both got 4 and Nia showed me the different outfits. They were playing with a camera earlier and wanted to take pictures – but then they got more interested in taking crazy pictures and did not stay on task so I had to take the camera away.
I then gave them 2 shirts and 3 pairs of pants each. Bel said 6 very fast, then Nia said 6. She could not really tell me or explain but I let it go.
With 2 shirts and 4 pairs of pants, I asked Bel to keep the answer to herself. Nia counted 11 (?). When I asked her to show me, she counted a shirt, the 4 pairs of pants, the other shirt then more pants and somehow got to 11. In the meantime, Bel whispered the right answered to me. I went back to the 2 shirts and 3 pairs of pants with Nia. She did the correct reasoning: she put all the pants with the first shirt, counted, then put all the pants with the other shirt, counted. Except she counted the shirts too (shirt+3 pants + shirt + 3pants). I corrected her and showed her how to count the outfits and not just each piece of clothing.
With 3 shirts and 4 pairs of pants, Nia counted correctly (she put the 4 pairs of pants with the first shirt (1,2,3,4) then with the second shirt (5,6,7,8) then with the third shirt (9,10,11,12). Bel took a little longer and did the same. She did not have 4 pairs of pants at hand but reused one of them and pretended it was a different pair. I thought that was inventive.
I was happy with what we got so far and did not want to add socks or sweaters this time.