Find the following values without a calculator.
Give your answers in this manner. (Eg 1, 2, 3, 4)
- 800 + 20 + _____ = 824
- 9000 + _____ + 30 = 9230
- _____ + 70 + 8 = 4078
- 50000 + _____ + 7 = 57807
(a)
800 + 20 + _____ = 824
820 + _____ = 824
824 - 820 = 4
(b)
9000 + _____ + 30 = 9230
9030+ _____ = 9230
9230 - 9030 = 200
(c)
_____ + 70 + 8 = 4078
_____ + 78 = 4078
4078 - 78 = 4000
(d)
50000 + _____ + 7 = 57807
50007 + _____ = 57807
57807 - 50007 = 7800
Answer(s): 4, 200, 4000, 7800