SUBJECT: 7th Grade General Math

TOPIC: Metric System Conversions

INTERACTITIVITY: Students have been studying metric conversions, so this bulletin board is to help them visualize mass conversions. Students have been supplied with seven bags, each being weighed 0.3 kg, 300 g, 3 dkg, 30000 mg, 0.03 hg, 30 dg and 30 cg. Three of these bags are equal to three other bags, while the seventh one is not. Students should try to see if they can convert these masses in their heads respectively to determine which bags are equal, and then check their answers with the scale. They can hand in the accompanying worksheet for extra credit points.

DIRECTIONS FOR USE: Symbolized by the scales, Libra (September 24 – October 23) is in constant pursuit of harmony and balance. Libra’s ruler Venus, the Goddess of love and beauty, possesses seven bags of sapphires, but they are all weighed in different metric units. There are three pairs of bags that are equal to each other, and one bag does not have an equal counterpart. Help Venus achieve her balance by finding the three pairs so she can discard the seventh bag.

- Pick a sapphire bag out of the blue bag.
- Notice that it is labeled according to its metric mass. Try to find its counterpart by using metric conversions mentally. Do not weigh any bags yet.
- Once you think you have found a bag that has an equal mass to the previous bag, weigh the bags on the scale and see if you were correct. (If the two bags are equal, then the scale should be balanced).

- Continue steps 1 – 3 until you have found all 3 pairs. Remember, one bag will not have an equal counterpart.
- Answer the questions on the rest of this work sheet. You have until next Friday to complete this, in which you can earn up to 10 bonus points on the next test.

TIME: 20 minutes

SPECIAL CONSTRUCTION: The scale was made out of a coat hanger, string, and two bowls. In order to the make the balance equalize, I tied three strings to both bowls. The border is made out of ribbon, and I had to outline the gold goddess myself.

CREDIT: Depending how many answers are correct, students can receive up to 10 extra points on their next test.