How do you write 21.75 in words?

To write 0.45 as a fraction in simplest terms, start by writing it as a fraction. 0.45 is 45 hundredths, so the fraction is 45/100. Next, you need to find the GCF of 45 and 100. You know that 5 will divide evenly into both numbers, and that dividing 5 into the numerator and denominator is 9/25. Since there are no factors that will divide into 9 and 25, the fraction is in simplest form.