Brushing your teeth takes a lot of math. Depending on your age, you might have 10, 20 or even 30 teeth, and that number could change tonight. Plus you have to brush for 2 minutes and hit every tooth in that time, spending 30 seconds on each quarter of your mouth. It’s serious business. Maybe that’s why our friend Audrey A. asked, how much toothpaste would a Komodo dragon use in a year? Well, that big lizard has 60 teeth, and those chompers can be up to 1 inch long. So dragons definitely need more toothpaste than people. Read on to figure out how much!

*Wee ones:* If you’ve brushed your teeth for 1 minute, are you done yet?

*Little kids:* If you start November with 8 teeth, then lose 2 teeth, then grow 1 new tooth, how many teeth do you have now? *Bonus:* If a Komodo dragon uses 2 feet of dental floss every day, how many feet does it use in a week (7 days)?

*Big kids:* Your pet dragon doesn’t brush enough, and gets a cavity in every 4th tooth (starting with the 4th) and in every 6th tooth (starting with the 6th). What’s the first number tooth that gets 2 cavities? *Bonus:* Say a Komodo dragon has twice as many teeth as a person, and each tooth has 4 times the area to brush. If a person uses 7 ounces of toothpaste in 1 year, how much does the Komodo dragon need?

Answers:

*Wee ones:* No, you need to brush for 1 more minute!

*Little kids:* 7 teeth now: 8 – 2 = 6, 6 + 1 = 7.* Bonus:* 14 feet: 2 + 2 + 2 + 2 + 2 + 2 + 2.

*Big kids:* The 12th tooth, since that’s divisible by both 4 and 6. We have to wait till the 24th tooth…can you figure out why not? *Bonus: *56 ounces, because there’s 8 times as much tooth area (4 x 2) to brush.