A bus travels at 40 km/h. How long does 200 km take?
5 hours
Time = distance ÷ speed = 200 ÷ 40 = 5.
Day 048Constant Speed
Standards 6.RP.A.3b
LEARNING TARGET
I can solve constant-speed problems using a rate per hour.
01 · LEARN
Build the idea
At a constant speed, distance = speed × time. Divide distance by time to find speed, or distance by speed to find time. Keep units consistent before calculating.
A bus travels at 40 km/h. How long does 40 km take?
1 hours
Time = distance ÷ speed = 40 ÷ 40 = 1.
02 · PRACTICE
Your turn
Work in order. Start with the foundations, then build toward explanation and application.
A cyclist travels 80 km in 2 hours at constant speed. Find the speed.
A bus travels at 20 km/h. How long does 120 km take?
A cyclist travels 100 km in 5 hours at constant speed. Find the speed.
A bus travels at 10 km/h. How long does 40 km take?
A cyclist travels 245 km in 7 hours at constant speed. Find the speed.
A bus travels at 40 km/h. How long does 200 km take?
A cyclist travels 30 km in 3 hours at constant speed. Find the speed and the distance in 2 hours.
A bus travels at 40 km/h. How long does 60 km take?
A cyclist travels 125/2 km in 5/2 hours at constant speed. Find the speed and the distance in 4 hours.
A bus travels at 35 km/h. How long does 245/2 km take?
03 · CHECK
Answers and reasoning
Reveal the teacher answer key
- 40 km/h
Speed = 80 ÷ 2 = 40; distance = speed × time.
- 6 hours
Time = distance ÷ speed = 120 ÷ 20 = 6.
- 20 km/h
Speed = 100 ÷ 5 = 20; distance = speed × time.
- 4 hours
Time = distance ÷ speed = 40 ÷ 10 = 4.
- 35 km/h
Speed = 245 ÷ 7 = 35; distance = speed × time.
- 5 hours
Time = distance ÷ speed = 200 ÷ 40 = 5.
- 10 km/h; 20 km
Speed = 30 ÷ 3 = 10; distance = speed × time.
- 3/2 hours
Time = distance ÷ speed = 60 ÷ 40 = 3/2.
- 25 km/h; 100 km
Speed = 125/2 ÷ 5/2 = 25; distance = speed × time.
- 7/2 hours
Time = distance ÷ speed = 245/2 ÷ 35 = 7/2.