How will you explain to your students that when you add or subtract fractions you must have a common denominator but you do not need one with multiplication or division????
This is not easy to explain but let me start by explaining what a common denominator is. The denominator is the bottom number and common means that both are the same number. In addition and subtraction they need to be the same so that when you do the math the number you time it by can go into both common denominator an even time. When it comes to multiplication or division it does not matter because you are flipping the number and doing the oppose. If you are doing division you actually work the problem doing multiplication is order to get the correct answer. This is hard to explain so I hope I did ok.....................
