I am trying to start again with math, giving it a second shot after i completly gave up on math for about 10y. I looked up multiple cheet sheets and rules, but they all say different things. My problem especially +29 – +59. The rule thing i got from the internet says + – + = larger integer’s sign, but then another tutorial said well if you reverse + and -, then you can get the answer that way, but they are 2 different answers. And i’m confused too about what, like what’s the point of doing the operations if we can just change whatever symbols we want, but then we do but nothing matches as the result so i’m just confused.
I just don’t get it, none of the rules match and in my head none of it even makes any sense. So i feel like i need to memorize the rules, but there are no rules. Pls help, i started crying due to the fustration because now i remembered why i despised math so much.
Update: I started being able to complete operations, even of 5 in a row. Thank you all! Ended up dropping tje unecessary + and just – – = + idk, but i’m doing it.
In: 2
I’m going to open with a follow-up question:
What do *you* think +29 – +59 should be?
The only real rule of adding and subtracting integers that I’m aware of is that subtracting a negative number is the same as adding a positive number, e.g. 2 – (-3) = 2 + 3.
That doesn’t apply in your case, your problem is just 29 – 59. Since 59 is larger than 29, the answer will be a negative number.
I’m pretty confused. Why are you putting “+” in front of the positive numbers? It’s redundant, numbers are assumed to be positive unless there’s a minus sign in front.
If you remove the redundant “+” from your numbers, that rule works. 29 – 59 = -30. The absolute difference between 29 and 59 is 30, then since 59 is the negative number and is larger, the answer will be negative.
Are you an adult?
When I tutored math and I was working with some from the ground up here’s how I thought of adding and subtracting. Take a long piece of tape and tape it to the floor, find the middle of it and make that 0. Now to left is the negative numbers and to the right is positive, all the numbers that exists live on this line. Positive as you know is given by a + and negative is shown with a – , this will be important to remember.
The symbols +,- tell us how far from 0 we are on the number line, so -5 is 5 spots to left on this number line. When doing math with numbers the important thing to remember is when a number is given by its self it’s assumed positive (e.g., 54 and +54 are the same number). So start small, 2 steps away from 0 plus 2 more steps from 0 means your 4 steps from 0 (2+2=4). Now start at 0 and take 3 steps to the right (positive) and then take 5 steps to the left, your now at negative 2 (3-5=-2).
Eventually you will realize the bigger number wins and the sign goes with it. Another example is 35-4=31, the 35 is positive but 4 is negative, the 35 is larger so it’s sign carries through to the answer. If it was reversed, -41+7=-34 then we can see the bigger number (-41) took its sign all the way through the answer (-34). Hopefully this helps a bit, I do recommend drawing out some sort of number line to help visualize where numbers are in relation to 0. Good luck!
Not sure where you are located but where I’m from we don’t write the + sign in front of positive integers, only for negative integers. That might be a source of confusion.
So
29 – 59 = -30, because:
29 –
59
_____
9 – 9 is 0, and 2 – 5 is -3.
It might be hard to understand in text form like this, I recommend this free resource for learning math. You can start from the VERY beginning of numbers and work your way up at your own pace:
https://www.khanacademy.org
Good luck! Please don’t give up on math! It can help you understand so much in this world!
Adding a number to another number means counting that many times past it. For example, to calculate 4 + 3 you count three times past four: five, six, seven – so the answer is 7. To calculate 3 + 6 you count six times past three: four, five, six, seven, eight, nine – so the answer is 9. And so on.
To subtract a number from another number is to count that many times back, or down. So to calculate 5 – 3 you count three times down from five: four, three, two – the answer is 2. To calculate 7 – 4 you count four times down from seven: six, five, four, three – the answer is 3.
If the second number in the subtraction is larger than the first one then you go into negatives. To calculate 2 – 3 you count three times back from two: one, zero, minus one – the answer is -1. To calculate 3 – 5 you count five times back from three: two, one, zero, minus one, minus two – the answer is -2.
That sounds overly-complicated and poorly taught. Overly-complicated and poorly taught explanations are a big reason why students hate their math classes in school, which is a shame imo.
When you say that using whatever rule, it’s possible to get different answers, that’s ambiguity, which ideally we want to avoid when trying to learn math, so I’m going to rewrite your problem. The extra plus signs are a bit confusing to read, and it might be easier to add instead of subtract. Instead of
+29 – +59
it might help to think about it as
29 + (-59)
I’ve TA’d math courses, and it’s much easier to explain things through a dialogue, as opposed to just typing out explanations. If you’re really interested in understanding math, I’d encourage you to spend a short amount of time thinking about how you would answer the rewritten problem and then ask any follow up questions that come to mind
I believe what you’re referring to as, the second rule is this: y – (+x ) = y + (-x). Using your example, 29 – 59 = -30 = (29) + (-59)
When I teach this to kids I tell them to think of positive integers (+) as money you have and think of negative integers (-) as money you owe. If I start with +29 dollars but then I have to give away (subtract) +59 dollars, then I now owe 30 dollars (-30).
You have found over-complicated explanations. You never need to write the (+) in front of numbers.
+29 – +59
is the same thing as
29 – 59
That’s “29 take away 59”, so you know *without memorizing any math rules* that the answer will be negative. If you have 29 and you remove 59, that’s going to end up less than zero, right?
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