How do i multiply this ? 320.7 million x 72.36 million ? do i have to write out all the zeros?

2 Answers
Feb 22, 2018

No you don't have to write all the zeros we use a technique that is called exponents and index

Explanation:

320,700,000= 3.207 xx 10^8

72,360,000= 7.236 xx 10^7

now, multiplying the above numbers using power index laws

(3.207 xx 10^8) xx (7.236 xx 10^7)

To muliply with the same bases the exponents (powers) are added up like:
10^8 xx 10^7= 10^(8+7)= 10^15

and simply multiply the rest using arithmetic
3.207 xx 7.236 = 23.205852

Thus, the answer will be
23.205852 xx 10^15

Which is written as 2.320582xx10^16

Feb 22, 2018

23,205.852 " million"

or

23.205852 " billion"

Explanation:

No, you do not need to write all the zeros.

The question was asked with millions in words, so you can just multiply and answer in millions as well.

320.7 million xx 72.36 " million"

= (320.7 xx72.36) " million"

=23,205.852 " million"

This can now also be read as:

23.205852 " billion"