Curriculum › Math ›Grade 6

Grade 6 Math · Level 2, Ratios, Rates & Percent

Constant Speed

How the lesson starts: Constant Speed

1. Road trip!

   Hi there! Aunt Rosie is taking the twins, Kai and Lia, on a road trip to the beach. Her van rolls along at a steady 50 miles per hour. That means every hour, they go 50 more miles. How far will they get in 3 hours? Let's ride along!

2. Hop by the hour

   Each hour is one hop of 50 miles. Hour 1: 50 miles. Hour 2: 100 miles. Hour 3: 150 miles. So 50 × 3 = 150 miles. When you know the speed and the time, multiply. Distance = speed × time.

3. How long will it take?

   At the beach, Kai bikes 36 miles at 12 miles per hour. How many hours? Count the 12-mile hops that fit in 36: that's 36 ÷ 12 = 3 hours. Time = distance ÷ speed. Watch out: 36 × 12 = 432 hours makes no sense!