Lesson Pages:

### Lesson Information

##### Standards, Description, & Download

**Grade: **6-7

**Standards: **7.RP.3

**Description:** Students will compare the bubble blowing ability of regular chewing gum to bubble gum and find the percent of change that will allow them to write a convincing ad for the bubble gum. Students will utilize the concepts of percent of change to accomplish this.

I had one of my former students come up to me today and ask when we were doing this lesson and could she come in to help with it. Clearly a memorable lesson if she remembers it over a year later! That made my day.

We will be starting the percent of change lesson on next week. I am going to use this lesson.

This lesson is a great idea BUT… isn’t the formula to find percent of change suppose to divide by the original amount? So then in the lesson plan it should read, “12-4=8; 8/4=2; 2×100= 200%”. So the bubble gum produces 200% more bubbles than the mint gum… which makes more sense because 117% would not show that the number of bubbles made with mint gum was doubled. Right?

Your absolutely right – i can’t believe I didn’t catch that. Dividing by the bigger number doesn’t make any sense at all… not sure what I was thinking… I’m going to fix that now and re-upload. Thank you for the catch!