Cancel the zero pairs in the following two sets of tokens. On what floor is the lift attendant in each case Class 6

Cancel the zero pairs in the following two sets of tokens. On what floor is the lift attendant in each case Class 6

Question 1.

Cancel the zero pairs in the following two sets of tokens. On what floor is the lift attendant in each case? What is the corresponding addition statement in each case? Class 6

Solution:

(a)

(+3) + (-5) = -2. Floor -2

(b)

(+6) + (-3) = +3 Floor +3.

Question 2.

Evaluate the following differences using tokens. Check that you get the same result as with other methods you now know : Class 6

(a) (+ 10) - (+ 7)

(b) (- 8) - (- 4)

(c) (- 9) - (- 4)

(d) (+ 9) - (+ 12)

(e) (- 5) - (- 7)

(f) (- 2) - (- 6)

Solution:

(a) +3, (b) -4, (c) -5, (d) -3, (e) +2, (f) + 4.