Find the factors of 21 . What factor comes next? \( 21: 1,[?],, 21 \)

The factors of 21 are 1, 3, 7, and 21. So in your sequence, the next factor that comes after 1 would be 3. Thus, it will look like this: \( 21: 1, 3, 7, 21 \). If you ever find yourself puzzled by factors, remember that they are simply numbers that divide evenly into another number. It's like finding out how you can divide up a pizza into equal slices! When working with numbers, start by testing smaller numbers as potential factors, which can help simplify the search significantly.