Express the diameter of the earth at the equator, 12700 km, in scientific notation

You must express whatever number you are given as something between 1 and 10. The rest is in powers of 10.

12700 = 1.2 which is between 1 and 10.

The rest is in powers of 10. You have to move the powers of 10 in the number of places you have to move the decimal.

To get to 1.2 you have to move the decimal 4 places. So the powers of 10 is

10 will be expressed as 10^4.

Answer: 1.27 * 10^ 4 km

The scientific notation is 4.0075 x 10^7 m

Explanation:

In this case, the Earth's circumference at the equator which is equal to 40,075,017 m can be expressed in terms of scientific notation by multiplying it to a factor of 10.