Lately, math teachers have been living in fear of two numbers: six and seven.
If you say them together in class, “Turn to page 67,” or “Do problems six and seven” chaos erupts. Students throw up their hands, yell “Six Seven!” and…

Lately, math teachers have been living in fear of two numbers: six and seven.
If you say them together in class, “Turn to page 67,” or “Do problems six and seven” chaos erupts. Students throw up their hands, yell “Six Seven!” and…