Scott baked a batch of rolls. He gave a bag of 10 rolls to each of 7 friends he kept 1 roll for himself. How many rolls did he bake in all

7 times 10 is 70, so in total the friends got that amount, but we aren't done, because we still need to add the roll that he kept for himself, so it's 71. Notice that it didn't say he left a whole bag for himself, just one roll.

10*7=70 70+1=71. 71 is the answer