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ADDING AND SUBTRACTING: When you add and subtract Integers, an easy way to get the correct answer every time is if you use a number line:  and when you are subtracting you will move down the number line (left).** Examples of Adding and Subtracting Integers: -3 + 1 = -2 First you will find the number -3 on the number line, then because you are adding you will move up (right) 1. The number that you are now on, -2, is the sum (answer) to the question. Another eg: 2 – 4 = -2 First you will find 2 on the number line, then you will move down the number line (left) 4. The number that is one the line is your answer to the question, –2. Subtracting a negative: 3 - -2 = 3 + 2 = 5 The double negative becomes a positive, so it's really just 3 + 2. Combinations: -6 - -8 = -6 + 8 = 2 Here you have to change the double negative to a positive. Then you start at negative 6 and move to the right on the number line by 8 places. You end up at positive 2. MULTIPLYING & DIVIDING: **When you are multiplying or dividing integers: **
Examples of Multiplying Integers: 2 x 2 = 4 The first number is a positive 2 and the second number is a positive 2, so your product would be a positive 4. -2 x 2 = -4 The first number is a negative 2 and the second number is a positive 2, which makes the product a negative 4. -1 x -2 = 2 The first number is a negative 1 and the next number is a negative 2, which makes the product a positive 2. Examples of Dividing Integers: 4 / 2 = 2 First you have a positive 4 and then you have a positive 2, which would make your quotient a positive 2. -4 / 2 = - 2 The first number is a negative 4, and the second number is a positive 2, which makes your quotient a negative 2. -4 / -2 = 2 The first number is a negative 4 and the second number is a negative 2, which will make the quotient a positive 2. |