Think about how many meals you eat in a week. Then imagine feeding all the animals in a zoo! An elephant eats in 10 days what one of us eats in an entire year (as much as 350 pounds of food each day). A hippo eats 88 pounds of lettuce, hay and veggies per day, and a giraffe eats 75 pounds of tree leaves. It adds up fast: each year the St. Louis Zoo has to buy 20 tons of fish, 5 tons of carrots, a whopping 85 tons of pet-food pellets, and tons of other stuff like earthworms. Yum!
Wee ones: Which weighs more, 6 tons of earthworms or 5 tons of fish?
Little kids: If you’re in charge of the 20 tons of apples each year, what numbers do you say to count the tons? Bonus: If the horses eat 3 tons of the apples and the guinea pigs eat 1 ton, how many tons of apples are left for everybody else?
Big kids: Each St. Louis zoo worker moves 700 tons of food every year! If that includes 200 tons of hay and 300 tons of earthworms, how many tons of other food does that leave? Bonus: About how much food total does that worker move each day? (Reminder: One year has 365 days.)
The sky’s the limit: If in 10 days an elephant eats what we eat in a year, how many years of our eating does the elephant eat in one year?
Wee ones: The 6 tons of earthworms.
Little kids: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, 20. Bonus: 16 tons, since they’ve already eaten 4 tons (3+1).
Big kids: 200 tons of other stuff. Bonus: About 2 tons per day, since we have 365 days…if a year had 350 days, it would work out to exactly 700.
The sky’s the limit: 36 1/2 years, since there are 36 1/2 sets of 10-day chunks in our year.
Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.