Find the following values without a calculator.
For 4 and 7,
- what is the first common multiple?
- what is the second common multiple?
- what is the fourth common multiple?
(a)
Multiples of 4: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48
Multiples of 7: 7, 14, 21, 28, 35, 42, 49
First common multiple = 28
(a)
28 x 2 = 56
Second common multiple = 56
(a)
28 x 4 = 112
Fourth common multiple = 112
Answer(s): (a) 28; (b) 56; (c) 112