# I want to learn about: Divisibility

• Why is it useful to know the divisibility of a number?  It allows us to determine whether a number is divisible by another number without having to divide them. In this post we are going to learn the divisibility guidelines for 9. Criteria for the divisibility by 9:   A number is divisible by 9 if […]

• How can we find out if a number is divisible by 7?  In this post we are going to look at the divisibility guidelines for the number 7. One of the ways to find out is by dividing the number by 7.  If the remainder is zero, we know that the number is divisible by […]

•   Divisibility?  What is that? Divisibility is when we divide number A by number B and the remainder is zero.  In this case we say that A is divisible by B. For example, is 1368 divisible by 6? To find out we divide 1368 by 6: When we divide it we see that the remainder […]

• Today we are going to learn about prime numbers and composite numbers. What is a prime number? A prime number is a number (greater than 1) that is only divisible by 1 and itself. What are composite numbers? They are numbers (greater than 1) that are not prime. They are divisible by 1, by itself […]

• In this post we are going to learn what the Greatest Common Factor (GCF) is and how to calculate it. What is the Greatest Common Factor (GCF)?  It is the biggest number that divides exactly into two or more numbers. Terms: Factor: A factor of a number is a number that divides evenly into the […]

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