How would you help Alberta with population growth?

Many thanks to Evelyn Lamb for the tip! Many thanks to @MathUpdate for sharing the image!

Categories

- Post author By mpershan
- Post date March 27, 2013
- 2 Comments on Help Canada with Percentages

How would you help Alberta with population growth?

Many thanks to Evelyn Lamb for the tip! Many thanks to @MathUpdate for sharing the image!

## 2 replies on “Help Canada with Percentages”

How would I help Alberta with population growth?

How about having more babies?

I think this illustrates an ambiguity that often arises when we work with percentages. Namely, what’s the denominator? In different circumstances it makes sense to talk about the percentage of the initial condition or final condition. In this case, the person who made this chart knows how to find a percentage: you put the amount of change over the total amount. He or she was just inconsistent in whether the total amount is the initial or final value.

To avoid an error like this, or to at least be able to catch it when you make it, I think it helps a lot to do the steps slowly. What is 50% of 2.7 million? (1.35 million). Now add that to 2.7 million. Do you get 5.4 million? But doing things slowly is kind of my default advice to people who are making mistakes on their math homework.