Adding and subtracting measurements is similar to adding and subtracting whole numbers. You just have to know how regrouping works. The basic idea here is the same as "carrying" and "borrowing" (or "regrouping") in ordinary addition. You need to be able to convert inches to feet or feet to inches in order to have enough of each unit to do the work. Let us work through these: 4 ft 7 in + 2 ft 10 in = 6 ft 17 in. How about subtraction? 11 ft 6 in - 2 ft 8 in = ? This cannot be done as it stands, because 6 in aren't enough to take 8 from. But there is an extra supply of inches right next door in the feet, so we go over and borrow a foot's worth of them: 10 ft 18 in - 2 ft 8 in = 8 ft 10 in. Again, it is just like borrowing in ordinary subtraction, but we use 12 instead of 10. Instead of converting 10's to 1's, we convert feet to inches.

Yesterday it was negative nineteen degrees Fahrenheit. I asked my daughter if she knew what would happen if the temperature were to be raised fifty degrees. She had no idea. I told her that water would still freeze (because it would still be thirty-one degrees). This math blew her mind. These are common things that students will learn about in this section. The focus here is on the sum and differences of like unit of measure. These worksheets explain how to do simple addition and subtraction, using terms of common measurements for length, mass, volume, temperature, etc. Some questions involve converting word problems into numerals.