Help! I am 15 years old and I can’t subtract. I mean, not just ‘cant subtract in my head’, which other people think is ‘not being able to subtract’, but even when I do it on payper I can’t remember how to do it. When I finally do remember, I am left wondering, which side to I subtract from first? Do I go left to right or right to left? Do I subtract upwards or downwards? Amongst many more confusing questions.
It is more like me forgetting HOW to subtract, than actually being fisicaly inable to do so. Although sometimes I do forget what the numbers represent! And as for the ‘x’ and ‘+’ they are the same.
Does anyone have any tips in helping me learn to subtract? I have no problem with the ‘harder’ stuff such as geometry, but I find that with some aspects, not being able to subtract is quite hindering, quite obviously.
Any suggestions gladly appreciated!
With love,
Cassie
Re: Subtraction Problem
Does the concept make sense to you?
I mean, if I were to say “okay, you had $500 and I just took away $499, how much do you have left?” would you try to write down the problme and figure out which numbers to do what with, or would you realize that you’d have a dollar left over?
It’s important to figure out where the problem lies and then tackle it — if you count on using a calculator, you still have to count on understanding which numbers to push when.
Re: Subtraction Problem
Sue J is on to something, and it may go farther than that.
The best way to deal with this is to go right to the foundations and work with beads on an abacus.
7 - 3 means count out 7 beads and take away 3.
12 - 5 means count out 12 beads (1 full row of 10 and 2 more) and then take away 5.
Work up and do 35 - 13, 47 - 15, and so on. You don’t need to take as long at it as younger children do, but you do need to work through the actual physical meaning of the operations.
When you get to multiplication, 5 X 4 means make 5 rows of 4 each and count up how many, and go on to harder levels.
If you can get someone to tutor you through this, you can really improve your math (and also improve your algebra and geometry) as you develop a real meaning to attach it to.
Re: Subtraction Problem
Basically I get confused with direction of subtraction.
If I had, 75-34
I would wonder, Do I take the 4 from the 5, or the 5 from the 4? Do I take the 3 from the 7 first, or the 4 from the 5 first?
Even now I am still confused, I know the smallest number goes on the bottom, but when we get into carrying 10’s (from which side?) I get confused sometimes.
Thanks all for your helpful suggestions!
Cassie
Re: Subtraction Problem
Well, look at your numbers. Just what are you trying to take away from what? 75 minus 34 means you are going to take 34 away from 75. Yup, it’s sort of backwards in how they say it. But when you get confused, go back to that.
Okay, so you’ve got 75 and you have to get rid of 34 of it. To understand the process you have to understand what “75” is and what “34” is. That the 75 isn’t a 7 and a 5, it’s 70 and 5. The numbers work like the odometer on a car or a bike — when you get to nine, there’s no symbol for the next mile, so it bumps over to a 1 and a 0… ten. THat concept’s called “place value” and it’s important that you get it down so you can make sense of all this stuff (and I can’t tell from here if you’re thinking, “of course I know that!” or “I’m not sure about that…” )
Re: Subtraction Problem
Yes — use the abacus (available in most toy stores, just ten wires with ten beads each, in a frame) and that covers *both* the meaning of subtraction as taking away *and* the tens and ones of the base ten system. Get a couple of cheap abacus, and then you can go up to 200 also.
If the x and the + look the same to you, that’s not a math problem, it’s a reading issue. If it’s that you forget what to do with them, what about using a calculator?
While I can remember what to do with x and +, I cannot do math in my head. At all. The end result is that I need to use a calculator. Always. If this continues to be a problem for you, consider asking your parents for help in getting tested and having the school agree that you be allowed to use a calculator.