12 - 5 = 7 Just like with addition, we can use a part-whole model to help partition larger numbers to make them easier to deal with in subtraction problems. First, partition 35 into 30 and 5.

Students could get used to that connection and then, suddenly, have a problem where the “more” leads to a subtraction ... that the word problem at the end will be about addition.

Using addition and subtraction in multi-step problems. OLIVIA AND HASSAN:Ahh! Woohoo! HASSAN:Olivia, I think we're inside a computer. HYPATIA:How did you get here? This is the computer that runs ...