Retired Moderator
Joined: 07 Jun 2014
Posts: 4815
Given Kudos: 0
WE:Business Development (Energy and Utilities)
Re: QOTD#23 Find the value
[#permalink]
30 Apr 2017, 14:32
Explanation
Sometimes dealing with fractions is easier than dealing with decimals, and sometimes vice versa.
Here are both methods.
When multiplying decimals, count how many total digits or decimal places there are to the right of the decimal point, then put the decimal point that
many places to the left once you’ve done the multiplication. So (0.05)(0.5) = 0.025 (2 digits for 0.05 and 1 digit for 0.5, so 3 total digits and therefore 3 places to the left).
\((5)(0.005) = 0.025\)
They equal the same thing, so the answer is 1.
When dealing with fractions, just remember that for each decimal place, you add another zero on the bottom. So \(0.05 =\frac{5}{100}\) , because you put two zeroes on the bottom, one for each of the two digits to the right of the decimal point. Or, you could convert the decimals to fractions and then multiply:
TOP:\(\frac{5}{100}\times\frac{5}{10}= \frac{25}{1000}\)
BOTTOM: \(\frac{5}{1000}\times 5= \frac{25}{1000}\).
Again, you get the same fractions on the top and bottom. Hence answer is 1