Comparing very large and very small numbers
The diameter of the Sun is 1.4 ×
Suppose you want to compare the diameter of the Earth, with the diameter of the Sun.
- Diameter of the Sun =
- Diameter of the earth =
- Dividing the diameters
- Since
a m a n a m − n - which is approximately
- So, the diameter of the Sun is about
times the diameter of the earth.
Example 8
Let us compare the size of a Red Blood cell which is 0.000007 m to that of a plant cell which is 0.00001275 m.
- Size of Red Blood cell 7x
10 − 6 - Size of plant cell = 1.275 x
10 − 5 - Dividing the values
- Since
a m a n a m − n - we get the power is
- Converting the exponent:
7 x10 − 1 and 1.275 is approximately equal to - Hence it is
- So a red blood cell is
of plant cell in size.
Example 9
Mass of earth is 5.97 ×
- Mass of earth is
kg - mass of moon is
kg. - add the both masses
- Simplifying to get the same power
- multipling
5.97 x 100 then we get it is - add the values
- we get the result is
- Hence mass is
kg
Example 10
The distance between Sun and Earth is
During solar eclipse, the moon comes in between Earth and Sun.
At that time , what is the distance between Moon and Sun.
- Distance between Sun and Earth =
m - Distance between Earth and Moon =
- Subtract the both distances
- Here change the power
10 11 10 8 - Hence, both exponent powers are same.Now, subtract the values
- We get the value is
- Hence, Distance between Sun and Moon =
m
Example 11
Express the following numbers in usual form.
Match the below exponents