## Thinking Mathematically (6th Edition)

We know that 1 mile = 1.6 kilometers. We can convert the length of the Nile River from units of miles to units of kilometers. $4130~mi = \frac{4130~mi}{1}\times \frac{1.6~km}{1~mi} = 6608~km$ The Nile River has a length of 6608 km. The Amazon River has a length of 6400 km. The Nile River is longer by 208 km.