They are doing a few things wrong like how on the division kind of thing you can’t just forget about the first # and go back to it that is not how you do it. Also, their adding is wrong because you can’t add the right side then the left side with it. They got all of that to work because the first # 7 goes into 8 the second # of 28 and then they subtracted the 7 from the 8 and dropped the 2 and went from there. You can use a lot of #’s with this, but all that I found out was 3, 24, and 17 with each other then 4, 28, and 25. Also, you can use 6, 36, 15 and 2, 20, 10. I figured this out by just guessing the first # then I knew what it went into and had that as the second # and found the third # by doing their math. Then, I made sure that it worked with the addition part and they did!