Date: 01/30/2001 at 11:09:09 From: Bianca Peier Subject: Math What do you do with the remainder in division?
Date: 01/30/2001 at 12:20:31 From: Doctor Peterson Subject: Re: Math Hi, Bianca. What you do with the remainder depends on what you want to do with the result, and the meaning of the problem. You may have to tell me more about your question, such as what kind of division you are doing. Sometimes the remainder means just what it says, and should be part of the answer. If I have thirteen apples to divide among five people, and I want to give each one of the people only whole apples so they can take them home, then I divide ___2_rem_3 5 ) 13 10 -- 3 and say that each person gets two apples, and I have three apples left over - the remainder. The same thing would happen if I wanted to cut a 13-inch board into 5-inch pieces: I would get two pieces, with a 3-inch piece left over that I couldn't use (for this project, at least). If it doesn't matter what's left over (or you aren't asked), you might just ignore it. Other times, I don't mind having pieces. When we eat at home, I might be cutting up those apples to share, and each person will get not only the two whole apples, but his share of the three others - which would be 3/5 of an apple, since we can cut each apple into five pieces and give each person three of them. So in this case, the answer is 2 3/5 apples: we use the remainder as the numerator of the fraction, and the divisor as the denominator. When you want a whole number answer, you may have to look at the remainder just to decide whether to "round up" the answer. For example, if I have 135 students to take on a trip, and each bus can hold 60 students, how many buses will I need? I divide 135 by 60 and find ____2_rem_15 60 ) 135 120 --- 15 That means if I used two buses, I would have fifteen students left over who couldn't go! So I add one to the number of buses, and take three buses. If the remainder had been zero, I wouldn't have to do this. If you can't decide how to use the remainder in some particular kind of problem, write back and tell me about it. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.