Math = Love: Fractions Containing Zero N/O O/K Posters

Thursday, August 6, 2015

Fractions Containing Zero N/O O/K Posters

Guess what I'm posting today.  Yup.  Another poster.  :D  I won't be allowed to start decorating my classroom until late next week, so I've been compensating by making new stuff to decorate it with.

Back in January, Elissa posted her Dividing by Zero? posters that were inspired by this pin.  I decided these had to go in my classroom for the next school year.  I've used the N/O and O/K notation to remind students that it is not okay to divide by zero for a couple of years now.  But, a reminder on the wall is always handy.

I've found that my Algebra 1 students, especially, struggle with seeing the difference between a fraction that is undefined and a fraction that equals zero when working with slope.  It's like they see the zero and automatically assume the answer is zero without thinking about where the zero is in the fraction.

I made two letter-sized posters to remind students that a zero in the numerator is okay, and it equals zero.  A zero in the denominator is a big no-no, and it is undefined.  At first, I was frustrated that the word undefined wouldn't fit.  Then, I got excited that I could write the word vertically since vertical lines have undefined slope.  :D

I've uploaded the posters here as an editable Publisher file (will need to download the font "La unica") and a non-editable PDF file.

Once these are hanging up in my classroom, I'll be sure to update this pot with a picture.  


  1. I made a color version of this at