[solved]maths turn score into percentage

hi
does anyone have any way to do this without any calculator. i have searched the web but they all say do 21 divide 75 x100. im used to using the calculator to do this which gets me 28%.
turn a score of 21 out of 75 into a percentage
but i use paper and no calculator i get 21 divide 75 = 3 (r12) x 100 = 300, but answer should be 28%.
any other methods any one know please
Thanks any ideas please
Answer #1
just do this: 21 divide 75. You will get a decimal number, 0.28 which you times by 100%. That clears the 0. bit leaving you with 28%
Its basically the same for all fractions, the numerator divide the denominator and the answer x 100%
Answer #2
thanks
but thats what i got when i used the calculator but when i did it via long division i got 3 with remainder 12. which is not correct. is there any other methods. thanks again
Answer #3
that because you have it the other way round. Try having 75 on the outside and 21 on the inside. (75 on the left, 21 on the right)
Answer #4
hi thanks again but i seem to now be getting
0 remainder 75
75 over 21
please advice me again i not sure if im doing this bit right
thanks again
Answer #5
Don’t try and divide first. Look to simplify. Divide both by 3
so 21/75 is the same as 7/25. I divided the numerator and denominator by 3. Do you know what % means? it means OUT OF 100
95% is 95/100. 85% means 85/100. 1000% means 1000/100
so we have 7/25. Multiply both denominator and numerator by 4. 28/100=28%
alternatively, divide 7 by 25 = 0.28=28%
Answer #6
thanks yeah i think i got that one now, but i didnt get the bit about Multiply both denominator and numerator by 4, how did the 4 come from?
thanks
Answer #7
100 / 25 = 4
So you multiply both by 4, this only works if the result of 100 / denominator is a whole number
Answer #8
Since the denominator is 25, you have to multiply by 4 to get 100. Since the denominator is multiplied by 4, so is the numerator. Hence:
7 x 4 = 28
—
25 x 4 = 100
so you get 28/100 or 28%
edit: damn you didnt refresh on time
Answer #9
ah yes thank you all, i get it now. thanks all for your help much appreciated.