## Factor Pairs to 100

#### Aligned To Common Core Standard:

**Grade 4 Operations** - 4.OA.4

What Are Factor Pairs? To understand factor pairs, we have to go back to revising natural numbers. You see, every natural number is a product of at least a one-factor pair. For example, 19 has a single factor pair, which is 1 and 19, because 19 is present in the tables of 1 and 19 itself. The number 32 has many factor pairs, such as 1 and 32, 2 and 16, and 4 and 8. So, by definition, a factor pair are those two natural numbers that are multiplied to get a specific answer. Notice that 19 has a single factor pair. It is because 19 is a prime number, so it can be said that every prime number has a single factor pair. Let’s take another example by finding out the factor pair of 23. Can you think of any number of tables which answer 23? No? That’s right, 23 does not have another factor pair, because it is a prime number. A few other examples of factor pairs are given below. - 18 -> (1, 18), (2, 9), (3, 6). - 24 -> (1, 24), (4, 6), (8, 3) - 50 -> (1, 50), (2, 25), (5, 10)

### Printable Worksheets And Lessons

- Primes and Composite
Numbers Step-by-Step Lesson- We go over the difference between
primes (can only be divided by themselves and 1) and composites
(have more than 2 factors).

- Guided Lesson
- A real mix of skills here. Circle all the multiples of 12, list
factors from least to greatest, and divisibility.

- Guided Lesson Explanation
- Not to toot my own horn, but this explanation makes a great deal
of sense.

- Practice Worksheet
- A cool little activity I came up with. Color the primes green
and the composites yellow.

- Missing
Digit Multiplication 5-Pack - What is the missing digit to complete
these products.

- Factors
5-Pack - Find the factors of numbers.

- Prime or Composite Numbers
Five Worksheet Pack - Identify the integers as prime or composite.

- Matching Worksheet - Match the number and their second multiple. This is a good quick review.

#### Homework Sheets

We mix up the skills here. You will first look for multiples of a particular number, then write all of the factors of a number. We finish off the homework with a little divisibility practice.

- Multiples Homework - Circle all of the numbers that are a multiple of 9.
- Factors Homework - Write the factors of 20 from smallest to the largest.
- Divisibility Homework - Is the number 45411 divisible by 7?

#### Practice Worksheets

This really works on your understanding of multiples, divisibility, and factors. We really clear it up for you.

- Practice 1 - Find the final value of the following problem.
- Practice 2 - A mixed bag of question types.
- Practice 3 - Lots of circles here.

#### Math Skill Quizzes

The quizzes are also more mixed then other sections. You start by listing factors. We move on to determining if a number is prime or composite. We finish off with Odds or Evens.

- Factors Quiz - Find all the factors of each number.
- Primes Quiz - Name the numbers as Prime or Composite and list their factors.
- Odds or Evens Quiz - Find all the factors of and label each number as odd or even.