Make Math Moments Academy › Forums › Community Discussion › Water Cooler › Why does the inequality reverse when dividing by a negative number? › Reply To: Why does the inequality reverse when dividing by a negative number?
JonAdministratorJanuary 18, 2020 at 7:51 am
I think a number line is an excellent way to model this! As an example you can show visually on the number line 5 < 9 and then if when you divide both sides by -1 and you didn’t switch the inequality then you would get -5 < -9….. show this on the number line. Is this true? Kids will say nope becuase -5 is NOT ‘more’ to the left than -9 is.
What are you thougths?