How to use factoring to simplify fractions, and how to cross cancel (grade 6 math)
When simplifying fractions, or when multiplying fractions, you can cross out, or cancel, common factors from the numerator and the denominator. It can help to write the numerator and the denominator as (something times something), in other words to factor them. I show this process using multiple examples, going from simple to more complex.
In the second part of the lesson, I show you why we can simplify "criss cross" or cross cancel, when simplifying (reducing) fractions, or when multiplying fractions. It's a neat process and kind of fun, to look for numbers that have common factors, and to simplify them.
See also
Prime factorization — video lesson
Math Mammoth Grade 6 curriculum