Pinching Paper Clips

Last week, we had a real math dilemma...We were just about to start a "pinching paper clips" activity. We had 10 boxes of paper clips, wrapped in plastic. Each box said "100 paper clips." We pinched some paper clips out of a box and then wrote and solved some equations to see how many we still had in the box. Once we solved the equations, we checked our work by counting the paper clips left in the box. Did we come up with the same number...to all of our surprise, no!

We weren't sure if our math was incorrect, so we went back and checked our answer. Then we realized that maybe we didn't start with 100 paper clips. We talked about how we could prove it and we decided to count the paper clips. After we grouped the paper clips by 10s we realized we had 102 paper clips.

So these marvelous mathematicians decided that we should check all of the boxes to make sure they had 100. It is a good thing we checked because we ended up with boxes containing 98-102 paper clips.

Each box needed 100 paper clips, so these smarties started figuring out what to do with their extra paper clips. One group had 102 so they gave 2 paper clips to the group with 98. Another group had 99 so they took 1 from the group with 101. There were a lot of trades made and in the end, we ended up with 10 boxes...100 paper clips in each.

We then made a long number string and saw that:

100 + 100 + 100 + 100 + 100 + 100 + 100 + 100 + 100 + 100 = 1000

and

100 + 100 + 102 + 101 + 100 + 98 + 102 + 99 + 99 + 99 = 1000.

What was the best thing about this math discovery? The kids were so amazed that none of this was planned and that mathy moments can pop up and surprise us!

Have you had any surprising mathy moments this vacation?