Math 7 · Unit 2, Lesson 5: Percent Increase and Decrease · Tile 1 of 3
Same Amount, Different Percent
Town A and Town B
Finn reads this
Did it grow a lot or a little? It depends on where it started.
Two towns
Finn reads this
In 1980, Town A had 5,000 people and Town B had 6,000. In 1990, Town A had 8,000 and Town B had 9,000. Brian says they grew the same amount: each one added 3,000 people. Darlene says Town A grew more. Who is right?
Town A: 5,000 → 8,000, change 3,000Town B: 6,000 → 9,000, change 3,000
Both of them. Brian is right about the amount: 3,000 each. Darlene is right about the percent: for Town A, 3,000 out of 5,000 is 60 percent; for Town B, 3,000 out of 6,000 is 50 percent. The same change means more when you start smaller.
Town A: 3,0005,000 = 0.60 = 60% increaseTown B: 3,0006,000 = 0.50 = 50% increase
ElleMath-speak
Percent change compares the amount of change to the original amount.
FinnPlain English
The same jump counts for more when you start small.
Who is right about what?
NC standards: NC.7.RP.3.
Where to go next
Let me try a few5 problems on same Amount, Different Percent.
Next: Tile 2, Find the Percent ChangeAlways divide by where you started
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