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how to subtract and add positive and negative numbers

 Oct 28, 2015

Best Answer 

 #1
avatar+1975 
+10

I remember making a little thing about this about a year ago but I probably wouldn't be able to find it so I'll just recreate it again! (With examples)

 

Positive and Positive

I'm just assuming you already know how positives work :)

Adding:

1 + 2 = 3

Subtracting:

1 - 2 = -1

Multiplying:

1 x 2 = 2

Dividing:

1 ÷ 2 = 0.5

 

Postive and Negative (and vice versa)

Adding:

Whenever there is a negative during adding, if it is before the addition sign and there is a positive number after, just think of it as you have negative, but since you're adding a positive, it's taking away a negative. If there is a negative after the addition sign, the negative cancels out the positive and it turns into for example, 1 - 2 instead of 1 + (-2)

-2 + 1 = -1 or 1 + (-2) = -1

Subtracing:

Whenever there is a negative during subtracting, if it is before the subtraction sign and there is a positive number after, you simply subtract, so the negative number becomes bigger (technically smaller, but hopefully you get my drift). If there is a negative after the subtraction sign, the two negatives cancel out and turn into addition. (ex: 1 - (-2) = 1 + 2)

-2 - 1 = -3 or 1 - (-2) = 3

Multiplying:

Whenever there is a negative and a positive during multiplication, the negative always wins. The answer is always negative no matter whether the negative number is before or after the multiplication symbol.

-2 x 1 = -2 or 1 x -2 = -2

Dividing:

Whenever there is a negative and a posititive during division, it works the same as multiplication. The negative always wins.

-2 ÷ 1 = -2 or 1 ÷ -2 = -0.5

 

Negative and Negative

Adding:

Whenever there are two negatives during adding, the negative cancels out the addition sign and turns it into a subtraction sign

-1 + (-2) = -3 or -2 + (-1) = -3

Subtracting:

Whenever there are two negatives during subtracting, the negative and the subtraction sign cancel out and turn into addition.

-1 - (-2) = 1 or -2 - (-1) = -1

Multiplying:

Whenever there are two negatives during multiplication, the two negatives cancel out and the answer is always positive

-1 x -2 = 2 or -2 x -1 = 2

Division:

Whenever there are two negatives during division, they act the same as multiplication. The two negatives cancel out and the answer is always positive

-1 ÷ -2 = 0.5 or -2 ÷ -1 = 2

 

Hopefully this helps! :) Let me or anyone else know if you need more help or still don't understand

 Oct 28, 2015
edited by saseflower  Oct 28, 2015
edited by saseflower  Oct 28, 2015
 #1
avatar+1975 
+10
Best Answer

I remember making a little thing about this about a year ago but I probably wouldn't be able to find it so I'll just recreate it again! (With examples)

 

Positive and Positive

I'm just assuming you already know how positives work :)

Adding:

1 + 2 = 3

Subtracting:

1 - 2 = -1

Multiplying:

1 x 2 = 2

Dividing:

1 ÷ 2 = 0.5

 

Postive and Negative (and vice versa)

Adding:

Whenever there is a negative during adding, if it is before the addition sign and there is a positive number after, just think of it as you have negative, but since you're adding a positive, it's taking away a negative. If there is a negative after the addition sign, the negative cancels out the positive and it turns into for example, 1 - 2 instead of 1 + (-2)

-2 + 1 = -1 or 1 + (-2) = -1

Subtracing:

Whenever there is a negative during subtracting, if it is before the subtraction sign and there is a positive number after, you simply subtract, so the negative number becomes bigger (technically smaller, but hopefully you get my drift). If there is a negative after the subtraction sign, the two negatives cancel out and turn into addition. (ex: 1 - (-2) = 1 + 2)

-2 - 1 = -3 or 1 - (-2) = 3

Multiplying:

Whenever there is a negative and a positive during multiplication, the negative always wins. The answer is always negative no matter whether the negative number is before or after the multiplication symbol.

-2 x 1 = -2 or 1 x -2 = -2

Dividing:

Whenever there is a negative and a posititive during division, it works the same as multiplication. The negative always wins.

-2 ÷ 1 = -2 or 1 ÷ -2 = -0.5

 

Negative and Negative

Adding:

Whenever there are two negatives during adding, the negative cancels out the addition sign and turns it into a subtraction sign

-1 + (-2) = -3 or -2 + (-1) = -3

Subtracting:

Whenever there are two negatives during subtracting, the negative and the subtraction sign cancel out and turn into addition.

-1 - (-2) = 1 or -2 - (-1) = -1

Multiplying:

Whenever there are two negatives during multiplication, the two negatives cancel out and the answer is always positive

-1 x -2 = 2 or -2 x -1 = 2

Division:

Whenever there are two negatives during division, they act the same as multiplication. The two negatives cancel out and the answer is always positive

-1 ÷ -2 = 0.5 or -2 ÷ -1 = 2

 

Hopefully this helps! :) Let me or anyone else know if you need more help or still don't understand

saseflower Oct 28, 2015
edited by saseflower  Oct 28, 2015
edited by saseflower  Oct 28, 2015
 #2
avatar+130475 
0

Excellent, saseflower......!!!!!

 

[ That took awhile, huh  ???  ]

 

 

cool cool cool

 Oct 28, 2015
 #3
avatar+1975 
+10

Haha it really does take a bit of time, but it's fun to help out. Thank you CPhill!! :)

 Oct 28, 2015

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