The #DIV/0! error happens when the denominator (the number on the bottom) of an equation is zero. Many times you will want to display a 0 or NULL rather than the #DIV/0! error. Below is a simple way to accomplish this.
Rather than entering =A1/B1, use =if(B1=0,0,A1/B1), if you want a NULL to appear rather than zero, enter =if(B1=0,”",A1/B1).