Working Up to Counting Up
Date: 09/25/2003 at 23:10:22 From: Jane Subject: explaining how to make change My adult daughter was in LD classes. She works at a register all day now and wants to learn how to make change by counting up. She has been able to cover up for the fact that she does not know how but is petrified someone will find out she can't. I do not know how to explain it to her.
Date: 10/14/2003 at 11:47:06 From: Doctor Ian Subject: Re: explaining how to make change Hi Jane, As with anything else in math, the key is going to be to take it slowly, and start with simpler situations first. One way to approach it might be to help her see that counting up is one of many possible ways to do subtraction: Subtracting Decimals With Borrowing http://mathforum.org/library/drmath/view/58892.html Another way would be to get her to start concentrating on how to break a single problem into multiple problems. For example, if someone gives me a $10 bill for something that costs $7.33, I need to 1. Get to the nearest multiple of 5 cents. (In this case, add 2 cents, which gets me to $7.35.) 2. Get to the nearest multiple of 25 cents. (In this case, add 15 cents, which gets me to $7.50.) 3. Add enough quarters to get to the nearest dollar. (In this case, add two quarters, which gets me to $8.) Now I just need to get from $8 to $10, which I do in the same kind of way, but using bills instead of coins. One value of breaking it down this way it that it can make the process seem less intimidating. Each step is manageable, and if all the steps are manageable, then so is the whole problem, right? Another value of breaking it down this way is that she can practice the steps individually, until each one becomes second nature. For example, just have her work on step 1 (getting to the nearest multiple of 5 cents) until she can do it without thinking about it. Then move to step 2, and eventually to step 3. If she thinks that this is going to be too hard, it might be helpful to get her to think of other things that she's learned in the past, which seemed difficult at first but which now seem pretty easy. Sometimes being confident that you'll be able to learn something is half the battle in actually learning it. I hope this helps! Write back if you'd like to talk more about this, or anything else. - Doctor Ian, The Math Forum http://mathforum.org/dr.math/
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