Find the following values without a calculator.
Give your answers in this manner. (Eg 1, 2, 3, 4)
- 10 + 5 = _____
- 20 + 7 = _____
- 10 + 11 = _____
- 30 + 27 = _____
(a)
10 + 5 = 15
(b)
20 + 7 = 27
(c)
10 + 11 = 21
(d)
30 + 27 = 57
Answer(s): 15, 27, 21, 57