Find the following values without a calculator.
For 7 and 9,
- what is the first common multiple?
- what is the second common multiple?
- what is the fourth common multiple?
(a)
Multiples of 7: 7, 14, 21, 28, 35, 42, 49
Multiples of 9: 9, 18, 27, 36, 45
First common multiple = 63
(a)
63 x 2 = 126
Second common multiple = 126
(a)
63 x 4 = 252
Fourth common multiple = 252
Answer(s): (a) 63; (b) 126; (c) 252