+/- 10 Challenge

We were working with different forms of measurement during this week of class. We had already learned length and height, but we hadn’t learned weight yet. We usually study the metric system so we were going to be learning grams and kilograms. So I bought this little scale for about 3 dollars (20rmb) that gives figures in grams.

We actually had 2 challenges to this lesson; Monday was adding weights to produce a specified amount and on Tuesday we did the other which was the boats and the weight bearing challenge.

WEIGHTS (+/- 10 Challenge)

Students had to make a T-chart and then add several more rows in it by using their ruler to space things out correctly (division and measurement).

Then I gave them 4 different weights (250g – 1000g). The requirements were simple – they had to come up with the weights with an allowance of plus or minus 10g (too difficult to get the weights “exact”) using only 3 items or less. In addition, they could not use the same object twice. So if they used a bottle of glue in their first weight of 250g, then they could not use it again on any of the other weights.

The challenge was simple – whoever found all four weights first was the winner. I took charge of the scale, and they ran around the room looking for different combinations for the weights. It was really awesome. They were so into it… I actually think this might have been one of our best challenges. Kara ended up winning, but everyone else had gotten at least 2 of the weights and did excellent. They all knew their weights in terms of grams and kilograms at this point and it was an excellent lesson to teach addition and subtraction.

If you’d like to see the Float or Sink (Strongest boat challenge), I put it in another post – FLOAT vs SINK (boat challenge).

Anyways, I completely recommend this challenge as it did a great job in allowing the children to understand the beginning concepts of density and weight as well. Many of them thought the bigger the object, the heavier it would be and they started to realize that it wasn’t so.

Hope you enjoyed and let me know how it went in your classroom if you used it. If you have a lot of children, you may want to have more than one scale and delegate responsibility to the students if they are capable of sharing it without incident. I think now my students could do it because we’ve been working on fairness and sharing recently but at that time, there would have been some conflicts. So just a forewarning… because they move fast!

Good luck 🙂


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