90 likes | 201 Views
Combining positive & negative numbers. 5 + (-9) is read: positive 5, negative 9 5 – 9 is read: positive 5, negative 9 -15 + 8 is read: negative 15, positive 8 -7 + (-10) is read: negative 7, negative 10 -57 – 57 is read: negative 57, negative 57.
E N D
5 + (-9) is read: positive 5, negative 9 5 – 9 is read: positive 5, negative 9 -15 + 8 is read: negative 15, positive 8 -7 + (-10) is read: negative 7, negative 10 -57 – 57 is read: negative 57, negative 57 Read the problemA number is either + or –(a minus sign is a negative)
16 – (- 4) is read: 16 minus negative 4 -5 – (- 10) is read: negative 5 minus negative 10 12 – (- 18) is read: 12 minus negative 18 6 – 10 – (- 3) is read: positive 6, negative 10 minus negative 3 - (- 10) – 3 + 4 is read: minus negative 10, negative 3, positive 4 Look for double negatives-(- read as minus negative
16 + (+ 4) is read: positive 16, positive 4 -5 + (+ 10) is read: negative 5, positive 10 12 + (+ 18) is read: positive 12, positive 18 6 – 10 + (+ 3) is read: positive 6, negative 10, positive3 + (+ 10) – 3 + 4 is read: positive 10, negative 3, positive 4 Change double negatives –(- to +(+
-15 + (-5) is read: negative 15, negative 5, ADD these numbers =20, keep the sign, answer -20 -57 – 57 is read: negative 57, negative 57, ADD these numbers =114, keep the sign, answer -114 18 – (- 4) is read: 18 minus negative 4, becomes 18 + (+ 4) is read: positive 18, positive 4, ADD these numbers =22, keep the sign, answer +22 If signs are the same, add the numberskeep the sign
2.7 + (- 5.2) is read: positive 2.7, negative 5.2, SUBTRACT these numbers =2.5, keep the sign of the bigger number, answer -2.5 -3 – (- 5) is read: negative 3 minus negative 5, changed to -3 + (+ 5), SUBTRACT these numbers =2, keep the sign of the bigger number, answer +2 If signs are different, subtractthe numberskeep the sign of the bigger #
A positive number is an elevator ride up and a negative number is an elevator ride down. -10 – 3 + 4: down 10, down 3, up 4, you are on the negative 9 ‘floor’, answer is -9 -15 + 10 + (- 5): down 15, up 10, down 5, you are on the negative 10 ‘floor’, answer is -10 -3 + 3 + 10: down 3, up 3, up 10, you are on the positive 10 ‘floor’, answer is +10 Think elevator!!!
5 + (-5) = 0 - 3 + 8 = 5 - 10 – 3 + 4 = - 9 Think electricityevery + cancels a –what is left?
Think Red cards are negativeBlack cards are positive Positive 7, negative 6, positive 1, answer is +2 Positive 8, positive 1, negative 5, answer is +4