Geometry check my answer?
posted by Skye .
The diameter of a car tire is approximately 0.6meters. The warranty is good for 70,000 km. About how many revolutions will the tire make before the warranty is up? More than a million? a billion?
 my work
c=pi*d
c=3.14*0.6
c=1.884 meters
1km=1000 meters
so 1.884 divided by 1000 = 0.001884 km?
So more than a billion revolutions? Is this correct?

70,000 = 7*10^4 km *10^3 m/km = 7*10^7 meters
7*10^7 meters/1.884 meters/rev = 3.72*10^7 rev
37,200,000 revolutions
37 million and 200 thousand 
What does ^ mean?

^ means exponent
2^2 = 2 to the 2 power or squared
2^3 = 8
2^4 = 16 etc