Subtract 1-, 2-, or 3-digit numbers from 3- and 4-digit number with/without renaming
When a child learns to relate math to everyday questions, he will be great at it from the simplest addition all the way to trigonometry. To convert percentages, decimals and fractions is thus one essential skill.
Subtract 1- or 2-digit number from a 2-digit number with/without renaming
They're also available for nearly all grade levels. There are printable middle school, high school, elementary school, and even pre-school worksheets.