Figure out how many different outfits you can have!
Task
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.
A riddle
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.