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welcome to math with mr. J in this video
I'm going to cover finding a percent of
a number and we are going to do that by
multiplying the number by the fraction
form or decimal form of the percent and
as you can see there are three examples
that we're going to go through together
in order to get this down so let's jump
right into number one where we have 50
percent of 16 and again we need to
multiply that 16 by the fraction form or
decimal form of the percent I will do
both for number 1 so let's do fraction
form first and the fraction form of 50%
or any percent you just put the percent
over 100 percent means per 100 so 50
hundredths now whenever we have a
percent of a number of fraction of a
number or decimal of a number it is a
multiplication problem we can replace
the of with a multiplication sign so 50
hundredths times 16 and we'll put it
over one so that fraction still holds
the value of 16 we just have a numerator
and a denominator now now we multiply
straight across 50 times 16 is eight
hundred and 100 times 1 is 100 and
that's improper so we need to do 800
divided by 100 which is 8 now as you can
see that improper fraction answer 800
over a hundred got fairly large and
value those numbers so what we can do if
you know a simplified version of the
fraction right 50 hundredths is a half
those are equivalent fractions so we can
replace 50 hundredths with one half
multiply it by our number and we get 16
over 2 which is a lot more manageable
than 800 and 100 there so we get to 16
divided by 2 and we get the same answer
of 8 so again you can use the simplified
version of the fractional fractional
form of the percent so again what we did
we multiplied the fractional form of 50%
by 16 our next method you can do on the
decimal form of the percent times the
number and the decimal form of 50% is 50
hundredths right that's equivalent to
this fraction here it's just in a
decimal form times 16 and if we were to
multiply that out by hand or calculator
whatever the case may be you're going to
get to the same answer of 8 so again
decimal form of that percent times the
number 16 let's take a look at number 2
25 percent of 20 so we'll do the
fractional form first
remember percent means per 100 or out of
100 so 25 out of 100 times 20 25 times
20 gives us 500 100 times 1 is 100 and
we get to 500 divided by 100 improper to
a division problem there 500 divided by
100 equals 5 so 25 percent of 20 is 5
and again we can use the simplified
fraction of 25 hundredths which is 1/4
so just to show you another way here we
can do 1/4
times 20 and we get 20 over 4 which
gives us the same answer 5 and then the
decimal way the decimal form of 25% is
25 hundredths times 20 so again if we
punch that into a calculator or do it
out by hand we're going to get the same
answer of 5 and lastly number 3
65 % of 15 so in order to put a percent
to fractional form we put it over 100
multiply it by 15 we can go straight
across which we get 975 over 100 so we
need to convert out of that improper
fraction so how many whole groups of 100
out of 9 75 well 9 we have 75 left over
out of 100 so 9 and 75 hundredths I'll
put it in decimal form as well 9 + 75
hundredths or we can multiply by the
decimal form of 65 percent which would
be 65 hundredths times 15 multiply it
out and we're going to get the same
thing 9 + 75 hundredths so there you
have it there's how you find a percent
of a number multiply the number you're
finding the percent of by the fractional
form or decimal form of the percent and
you'll get that percent of the number
hopefully that helped thanks so much for
watching
until next time peace
