Originally Posted by Irena
Originally Posted by Dude
I see a middle ground here on the Legos question. Obviously the boy knew the difference was 10, so the teacher was just being dumb there. However, when he translated the problem into mathematical language, he did not write the correct expression.

Hmmm I guess this where my lack of math ability comes in but. I didn't realize you could only compare by subtraction.

You can compare many ways, but that's not the question. The question reads, "How many more legos are in the new set?" That's clearly a subtraction problem.