MATH MODULE GRADE 7 LESSON 4: OPERATION ON INTEGERS o ADDITION OF INTEGERS +8 HOW TO ADD INTEGERS USING THE NUMBER LINE Example: -5 + 8 = 3 o The first integer is you starting point. (-5) To add a positive number (8) means that we move the point to the right of the number line. Similarly, if we have to add a negative number implies that we move the point to the left of the number line The landing point is their sum. SUBTRACTION OF INTEGERS HOW TO SUBTRACT INTEGERS USING THE NUMBER LINE This method is just the opposite of adding integers Example: -5 - 8 = -13 The first integer is you starting point. (-5) To subtract a positive number (8) means that we move the point to the left of the number line. Similarly, if we have to subtract a negative number implies that we move the point to the right of the number line The landing point is their difference. Note: The operation used here is subtraction and the sign of 8 is positive, therefore you have to move the point eight times to the left of the number line. LESSON 4: OPERATION ON INTEGERS TRY THIS! o Add the following Subtract he following Example: Example: -8 + 8 = 4 + (-9) = -6 - 8 = - 4 - (-5) = -5 + 10 = -2 + (-3) = 14 - 7 = - 2 - (-8) = RULES IN ADDING INTEGERS ADDING INTEGERS WITH SAME SIGNS Adding integers that have the same sign is pretty straightforward. Add the absolute value of the numbers then copy the sign. Examples: 8 + 8 = 16 - 4 + ( -5) = -9 4 + 7 = 11 -15 + (-3) = -18 ADDING INTEGERS WITH DIFFERENT SIGNS When adding integers with different signs, you subtract the absolute value of two numbers and copy the sign of the number with higher absolute value. Examples: o -7 + 2 = -5 - 3 + (3) = 0 -4 + 10 = 6 15 + (-10) = 5 RULES IN SUBTRACTING INTEGERS KEEP, CHANGE, CHANGE (KCC) RULE When subtracting integers, we may use the KCC rule. Keep the minuend (-5) Change the operation to addition (+) Change the sign of the subtrahend (-12) -5 + -12 (apply now the rule in adding integers) So, the answer is -17 LESSON 4: OPERATION ON INTEGERS -5 – 12 = ?
