Five multiples of 42 are 210, 168, 126, 84 and 42. This is because 42 is a factor of each. A number is a factor of a given number if it can be multiplied by one or more other numbers to obtain the given number as a product.
To obtain five multiples of 42, it is multiplied by five, four, three, two and one. Because multiplication is the opposite of division, it is also true that a number is a multiple of another number if it can be divided by that number with no remainder.
Since the base of the Hindu-Arabic number system is 10, another simple approach to obtaining five multiples of 42 is to write additional zeros at the end. Using this approach, the resulting multiples are 420, 4,200, 42,000, 420,000 and 4,200,000.
Each of these numbers is also a multiple of 10. Since 10 is a multiple of two and five, half of any number generated by multiplying 42 by 10 is a multiple of 42 and some multiple of five. Hence, 210, 2,100, 21,000, 210,000 and 2,100,000 are multiples of 42.
One additional approach to obtaining multiples of 42 is doubling its value five times. Using this strategy returns 84, 168, 336, 672 and 1,344 as multiples.