Using Diagrams to Iterate Ratios
Kate and Christopher discover a way to solve proportional reasoning problems in a speed context, by drawing diagrams and repeating (iterating) a ratio of distance and time.
Kate and Christopher use the Races applet to find the number of miles and minutes the red car should travel to go at the same speed as the blue car, which travels 12 miles in 9 minutes. They note some patterns that work and others that don’t work.
Kate and Christopher use a diagram to find the amount of time it should take a car to travel 60 miles so it goes at the same speed as a car traveling 12 miles in 9 minutes.
Kate and Christopher see four little trips of 12 miles in 9 minutes in a diagram that shows a journey of 48 miles in 36 minutes.
Common Core Math Standards
Common Core Math Practices