Here's how we're going to do it: Now, remember, that's really 90 = 80 + 10! Now, here's the key to this whole trick: A 1 in the tens stripe is 10... and that's the same as 10 ones! < It's just like swapping a $10 bill for ten $1 bills! > Now, add the 10 and the 2 in the ones stripe: Now, we'll finish it off quick! Subtract the ones... Then, subtract the tens... Go to the next page for another one... It's going to feel a LOT easier the second time! Previous continue 1 2 3 4 5 6 of 6
