Step-by-step solution to find the factors and factor pairs of 21:
- If a whole number divides 21 evenly (remainder = 0), then it is a factor of 21 (divisor factor), and the corresponding quotient is also a factor of 21 (quotient factor)
- Divisor factors and quotient factors form a complete list of the factors and factor pairs of 21
- With the exception of 0, all whole numbers less than or equal to the square root of 21 (√21 ) are possible divisor factors of 21
- √21 = 4.5826
- Possible Divisor Factors of 21: 1, 2, 3, 4
- Filter list of possible divisor factors by testing divisibility of 21 by 2, 3, and 4
- Possible Divisor Factors of 21 (filtered): 1, 3
- Divide 21 by the possible divisor factors in the filtered list
- Factors of 21: 1, 3, 7, 21
- Factor Pairs of 21: (1*21) (3*7)
- Note: the first number in each factor pair is a divisor factor and the second number is a corresponding quotient factor
