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

Question

1386 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-02-22T17:43:13

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

#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#

Answer 2 · 2018-02-22T18:35:52

#23,205.852 " million"#

or

#23.205852 " billion"#

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"#