How do you change 912 to simplest form?

It is necessary to find a number that divides into both 9 and 12 in order to express a fraction in its simplest form. The largest number is ideal.
The largest number that divides into both in this situation is 3.
Now, multiply 9 and 12 by 3.
${\displaystyle \Rightarrow \frac{9}{12}=\frac{9÷3}{12÷3}=\frac{3}{4}}$ in simplest form
Usually, thask of dividing both numbers by 3 is performed mentally, stroking out the number and replacing it by the value remaining after division.This is called cancelling
${\displaystyle \Rightarrow \frac{9}{12}=\frac{3}{4}}$

Solution: 
The largest common factor between the denominator and the numerator must first be identified. 1 and 3 and 9 are the factors of nine. 1, 2, 3, 4, 6, and 12 make up the number 12. Therefore, 3 is the number that 9 and 12 have in common. Thus, multiply both sides by 3.So the simplest form of ${\displaystyle \frac{9}{12}}$ is ${\displaystyle \frac{3}{4}}$

Find the GCD (or HCF) of numerator and denominator
GCD of 9 and 12 is 3
Divide both the numerator and denominator by the GCD
$\frac{9÷3}{12÷3}$
Reduced fraction: $\frac{3}{4}$
Therefore, 9/12 simplified to lowest terms is 3/4.