Doing take aways I am reviewing take aways. I am having trouble
How do I do $342 - 58$?
For the ones column I made the $2$ into a $12$ so I can do $12 - 8 = 4$ but I must take away one tens. So I get $3 - 5$ in tens column but I cant do $3 - 5$. What do I do now do I borrow something else?

While some answers here have been doing it in different, and maybe more efficient methods, I'd like to explain as it seems like your teacher (probably) wants you to do it :)
When doing $342 - 58$, you start with $2 - 8$. This does not work, so you have to borrow a ten. $12 - 8 = 4$. This is the last digit, your ones. Now, since we borrowed a ten, we have to do $3 - 5$. We have to borrow from the first number, and we get $13 -5 = 8$. This is the second digit; your tens. Now, since we are left with $2$ after we borrowed from the three, we have $284$, or "two hundreds, eight tens and four ones." 
Best of luck with catching up, I know how hard it is to come from behind in math :)
If you are having trouble setting it up in a table, MJD's answer will help!
