## Thinking Mathematically (6th Edition)

We know that 1 mile = 1.6 kilometers. We can convert the length of the Yangtze River from units of miles to units of kilometers. $3940~mi = \frac{3940~mi}{1}\times \frac{1.6~km}{1~mi} = 6304~km$ The Yangtze River has a length of 6304 km. The Mississippi River has a length of 6275 km. The Yangtze River is longer by 29 km.