# Off to Work, with Water and Whales

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

# Off to Work, with Water and Whales

November 22, 2013

Grown-ups go to work every day by all different ways. They might walk, drive by car, take the train or even ride a bike. But one of the most scenic ways to ride to work is by ferry. In places where lots of people want to cross a river to reach a big city, boats called ferries ride back and forth all day, ferrying passengers to work and then back home at day’s end. According to Bedtime Math fan Alexa M., her dad has one of the best ferry rides of all: crossing Puget Sound from Bainbridge Island to Seattle, WA, over nearly 9 miles of waters where sometimes orcas splash up above the surface to peek at us. There are two ferries that make the crossing, the Wenatchee and the Tacoma, and each boat can hold up to 202 cars and 2,500 people! If we do the math, we can find out exactly how many people could take this awesome ride to work every day.

Wee ones: The Wenatchee makes 13 round trips a day and the Tacoma makes 10 round trips. Which ferry makes more trips?

Little kids: If the Tacoma makes 10 round trips every day and by midafternoon it’s done 6 of them, how many round trips does it have left?  Bonus: How many times does it cross the Sound in 10 round trips?

Big kids: The ferry takes 35 minutes to cross. If it waits 10 minutes to load before turning around, how long does it take to ride across and back?  Bonus: This cool graphic shows how full the ferries get: on weekdays they’re full in the morning heading to Seattle, and in the afternoon coming back. If the Tacoma carries the full 2,500 people on 4 of the trips to Seattle and just 1,000 on each of the remaining 6 trips, how many people ride the Tacoma to Seattle each day?

Answers:
Wee ones: The Wenatchee makes more.

Little kids: 4 round trips left.  Bonus: 20 times.

Big kids: 80 minutes (1 hour 20 minutes). Bonus: 16,000 people: 10,000 on the 4 full trips, and 6,000 total on the remaining 6.

A big thank-you to Alexa for the topic, and to Ms. Claiborne’s 1st grade class at Captain Johnston Blakely Elementary School for spreading the word about Bedtime Math!

### Laura Overdeck

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 while still in diapers, 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.