##75/100##

There are a few ways to visualise this but I will chose what I think is the simplest

If you know decimal places you can determine what value should be in the denominator of the fraction, let’s use the example number 123.45

In the example 3 is in the ones place, 2 is in the tens place and 1 is in the hundreds place

Decimals work the same way except backwards, for our example 4 is in the tenths place and 5 is in the hundredths place (notice the “th” at the ends)

If you can determine what the last decimal place is, then you simply place it over that value (so in the tenths place you use 10 as the denominator and so one)

So for your question the 5 is in the hundredths place so you place the whole number over one hundred

You then simplify ##75/100## to ##3/4##

(both values are divisible by 25, ##75//25=3## and ##100//25=4##