Complete these expressions. You may think of them as finding the movement needed to reach the Target Floor from the Starting Floor. a. (+1) − (+4) = _____ b. (0) − (+2) = _____ c. (+4) − (+1) = _____ d. (0) − (−2) = _____ e. (+4) − (−3) = _____ f. (−4) − (−3) = _____ g. (−1) − (+2) = _____ h. (−2) − (−2) = _____ i. (−1) − (+1) = _____ j. (+3) − (−3) = _____
−2
−3
−2
+3
+2
+7
−1
−3
0
+6
Explanation
(a) To go from Floor +4 to Floor +1, you need to go down 3 floors. Movement = −3. (b) To go from Floor +2 to Floor 0, you need to go down 2 floors. Movement = −2. (c) To go from Floor +1 to Floor +4, you need to go up 3 floors. Movement = +3. (d) To go from Floor −2 to Floor 0, you need to go up 2 floors. Movement = +2. (e) To go from Floor −3 to Floor +4, you need to go up 7 floors (3 floors to reach 0, then 4 more). Movement = +7. (f) To go from Floor −3 to Floor −4, you need to go down 1 floor. Movement = −1. (g) To go from Floor +2 to Floor −1, you need to go down 3 floors. Movement = −3. (h) To go from Floor −2 to Floor −2, no movement is needed. Movement = 0. (i) To go from Floor +1 to Floor −1, you need to go down 2 floors. Movement = −2. (j) To go from Floor −3 to Floor +3, you need to go up 6 floors. Movement = +6.