Find the following values without a calculator.
For 6 and 7,
- what is the first common multiple?
- what is the second common multiple?
- what is the fourth common multiple?
(a)
Multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48
Multiples of 7: 7, 14, 21, 28, 35, 42, 49
First common multiple = 42
(a)
42 x 2 = 84
Second common multiple = 84
(a)
42 x 4 = 168
Fourth common multiple = 168
Answer(s): (a) 42; (b) 84; (c) 168