Model 7 — The Unit Conversion Trap

04 Try it yourself Interactive

Five families, one habit

Pick a unit family and two quantities — the first in the larger unit, the second in the smaller. The walkthrough names both units, shows what the unconverted answer would have been, converts down, cancels, and then checks the result by counting chunks instead.

2.5 kilograms against 500 grams

2500 : 500 · 5 : 1 · not 1 : 200

Switch the family without changing the numbers. The same pair of numbers gives a different ratio in each family, which is the clearest possible demonstration that the units are part of the question.

Press Next to work through it one step at a time.

Conversion factor–

First, converted–

Ratio–

First ÷ second–

step 0 / 0