Adding and Subtracting positive and negative numbers

Integers are positive or negative numbers but have no fractional or decimal part. Integers are whole numbers that can be negative, positive, or zero. Adding and Subtracting positive and negative numbers is very simple if you understand the following four rules.

Negative Integers: Negative integers are less than zero.

Positive Integers: positive integers are greater than zero.

Thus, integers can be …, –3, –2, –1, 0, 1, 2,3, … and they are shown on the number line below.

As you go toward the right number gets larger while going toward the left number gets smaller. Four Rules of addition and subtraction are:

1. Adding and Subtracting positive and negative numbers: Adding two positive numbers

Add both numbers and the result is positive

In general math, you learned to add positive numbers to obtain their sum; thus, for example, 7 + 3 is 10.

2. Adding two negative numbers

Add both numbers and the result is negative.

Example -7-3 = -10. which means you add the numbers but the sign you give to them is negative

Another way you think of plotting -7 on a number line and then moving 3 steps in the left direction to add -3 to it. The answer you get on the number line is -10

3. Subtracting two positive numbers

Subtract both numbers and the number positive/negative.(Sign of bigger number)

If 7 and 3 are two numbers 7 – 3 = 4 while 3-7 = -4. It means you should subtract the numbers as you do but a sign of a bigger number is to be assigned.

Ignoring the sign on each number, subtract the lower number from the higher number and assign the result from the above subtraction to the sign that is associated with the higher number.

4.Subtracting two negative numbers

the number positive/negative.(Sign of bigger number)

For example -7-(-3) = -7+3 -4. This means in this case -(-) is becoming ‘+’ and so the number gets converted to +3. The above rule number 3 comes into the picture and the answer is -4

In the case of -3-(-7) = -3+7 = 4. This means in this case -(-) is becoming ‘+’ and so the negative number gets converted to +7. The above rule number 3 comes into the picture and the answer is 4

Examples of the pdf are from the math workbook with solutions from hackonmath.

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