The first thing to do is to subtract the ones... But, there's a big problem!
But, no worries... We can fix it! What we're going to do is borrow from the tens stripe. (Also called regrouping!) This is going to look funky at first, but you'll get it pretty easily after you do some of them. It's not that bad. Trust me! It's also a really good idea to grab a pencil or, even better, some colored markers and work these along with me!
Head on over to the next page and we'll get to work!