Adding, Subtracting, Multiplying, and Dividing Integers...
First off, what's an integer?
An integer is a whole number that isn't a fraction, decimal, or percent. It's whole numbers, both negative and positive. It is an number complete itself.
Now, how do I add, subtract, multiply, or divide one?
I'll show you...
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Add:
Same Sign (+ and + or - and -): Add and keep the sign.
Ex:
- 3 + 3 = 6
- -9 + (-6) = -15
Different Sign (+ and - or - and +): Subtract the larger number by the smaller number. Then keep the sign of the larger number.
Ex:
- -9 + 8 = -1 (9 - 8 = 1, and 9 is the larger number, so it must be negative)
- 6 + -8 = -2 (8 - 6 = 2, and 8 is the larger number, so it must be negative)
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Same Sign: Subtract and keep the sign.
Ex:
- 8 - 4 = 4
- -10 - (-7) = -3
Different Sign: Keep the first number, switch to addition, and make the negative positive, or the positive negative (a.k.a. add the absolute value).
Ex:
- 8 - (-4) = 8 + 4 = 12, so the answer to 8 - (-4) is 12.
- -7 - 8 = -7 + (-8) = -15 so the answer to -7 + 8 is -15.
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Multiplication: Easier Than The Other Two
For multiplication, you don't need to really worry about signs, except the fact that it determines the answer. Don't know what I mean? Well, here's how you can tell if the answer's going to be negative or not...
- If both numbers are positive, the answer is going to be positive.
- If both numbers are negative, the answer is also positive (I'll explain an answer to why later, not really but still...)
- If one number is negative, the other positive, the answer is negative, doesn't matter which comes first.
If you're multiplying with the same signs: Positive.
If you're multiplying with different signs: Negative.
But let's get to the easy part: actually multiplying multiplication...
You just multiply them. That simple.
Ex:
- 3 x 3 = 9 (since both numbers are positive, the answer is positive.)
- -6 x -9 = 54 (since both numbers are negative, the answer is positive.)
- -3 x 7= -21 (since one's positive, the other number negative, the answer is negative. Now get the sign thing? If not, consult your math teacher, because I have no other way to explain it to you. Your teacher might be able to help.)
That's it. Now isn't that easy?
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Division: Exactly like Multiplication
Now that you've revised multiplication, division shouldn't be that hard. It's the exact same thing as multiplication!!
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You just divide them, with the same sign rules as multiplication (same signs: positive, different signs: negative)
Ex:
- 8 / (<---- means division, I don't have the division sign) 2 = 4
- 6 / (-3) = -2
- -12 / (-2) = 6
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Well, there's integers. I hope you get it now. If you don't find some more help! It never hurts to find more help!
Sources: my teacher and notebook notes
--M Ann M
(The M's don't stand for math or math geek if you looked at my name you'd realize their my initials. My friend's made fun of that when I told them I started this, not saying any names...Carter, Justin, and Liv)
