Deer aren’t among the best-swimming animals, but that’s not stopping this one. A family in Freehold, NJ found a baby deer, or fawn, swimming in their backyard pool one hot day in June. As you can see in the video, the deer swims laps as if this is her pool! She came back the next day, and the next…the only day she skipped was the rainy one. The fawn used the pool as a way to cool off. The pool looks like a pond since its walls are painted a darker blue than most pools, and the water has salt, not chlorine. So if this fawn wants to train for the Olympics, she’s found her practice spot.

*Wee ones:* Deer have 4 legs. Stand with another person front to back to “be” a deer. Now walk like one: step with your left foot while the other person steps right, then switch feet!

*Little kids:* If the fawn swims 1 lap around the pool, then 2 more laps, then 3 more laps, how many laps has she swum? *Bonus:* If she wants to swim 10 laps total and is counting down, what number does she say for the next lap?

*Big kids:* If the fawn swims on a 75-degree day to cool off, then on a 93-degree day, and the 3^{rd}day’s temperature is halfway between those, how hot is the 3^{rd} day? *Bonus:* If there are 100 deer legs in the pool, how many deer friends did the fawn bring along?

*The sky’s the limit:* If the deer swims 1 lap the first day, 2 laps the next, 3 the next…on what day will she have swum 36 laps? Can you find a pattern to solve it without adding all the numbers?

Answers:

*Wee ones:* See if you can step with the correct foot!

*Little kids:* 6 laps. *Bonus:* 4, since she’s counted down, 10, 9, 8, 7, 6, 5.

*Big kids:* 84 degrees. The temperatures are 18 degrees apart, so the halfway mark is 9 degrees from either of them. *Bonus:* 24 deer, since there need to be 25 in total.

*The sky’s the limit:* On day 8. She swims 1 lap, then 3 total by the end of day 2, then 6 total, then 10…these are the “triangle numbers.” Each one is the day’s number times 1 more than that number, then cut in half. 36 is half of 72, which is 8 x 9, so it’s on day 8.

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.