Hi there! I am Studyfin, your math helper. Today we will explore how numbers are built!
Every whole number has factors. Factors are the numbers you multiply together to get another number. For example, 2 and 3 are factors of 6 because 2 times 3 equals 6.
A prime number is special because it only has two factors. Those factors are 1 and the number itself. We can think of it as a single straight line of blocks that cannot make any other rectangle shape.
A composite number has more than two factors. This means you can arrange its blocks into a neat grid or rectangle with multiple rows. For example, 6 blocks can make a 2 by 3 rectangle.
✏️ Worked example
Let us find out if the number 9 is prime or composite by finding its factors.
Find the first set of factors by starting with 1. We know that 1 times 9 equals 9.
Check if 2 is a factor. Since 9 is an odd number, 2 does not divide it evenly.
Check if 3 is a factor. We know that 3 times 3 equals 9.
List all the unique factors we found. The factors of 9 are 1, 3, and 9.
Count the factors. Since 9 has three factors, which is more than two, it is a composite number!
Want the full interactive lesson — quiz, animations, and Finn cheering them on?
Studyfin
✨ Sign up free
