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### Course: 4th grade > Unit 6

Lesson 1: Factors and multiples- Factors, multiples, and patterns: FAQ
- Understanding factor pairs
- Factor pairs
- Finding factors of a number
- Identify factors
- Reasoning about factors and multiples
- Finding factors and multiples
- Relate factors and multiples
- Identifying multiples
- Identify multiples
- Factors and multiples

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# Factors and multiples

Learn about factors and multiples and how they relate to each other.

## Factors

Factors are whole numbers that can evenly divide another number.

### Picturing factors

Factors give us a way to break down a number into smaller pieces. We can arrange dots into equal sized groups to help us picture the factors of $12$ .

Or, we can arrange $12$ dots in ${3}$ rows with ${4}$ dots in each row.

${3\times 4}=12$

Once we figure out all of the ways that $12$ dots can be arranged, we can look at the number of rows and number of dots in each row to find the factors of $12$ .

We can make $12$ with a row of ${5}$ and a row of ${7}$ . So are ${5}$ and ${7}$ factors of $12$ ?

No. ${5}$ and ${7}$ are not factors because the dots are not divided into equal sized groups.

### Finding factors without pictures

We can find the factors for $16$ without drawing dots by thinking about numbers that will divide into $16$ evenly.

The quotient, which is

The quotient, which is

In this case the quotient is

The factors of $16$ are ${1,16}$ , ${2,8},$ and ${4}$ .

Numbers like $3$ and $5$ are not factors of $16$ because they cannot be divided evenly into $16$ .

## Factor hints

Every number has $1$ as a factor.

Every number has itself as a factor.

## Factor pairs

Two numbers that we multiply together to get a certain product are called factor pairs. To get the product of $8$ , we can multiply ${1}$ $\times $ ${8}$ and ${2}$ $\times $ ${4}$ . So the factor pairs for $8$ are ${1}$ and ${8}$ and ${2}$ and ${4}$ .

Arranging dots in equal sized groups helps us to see that factors always come in pairs. One factor in the factor pair is the number of rows. The other factor in the factor pair is the number of dots in each row.

Let's find the factor pairs of $20$ . Remember, we are looking for two whole numbers that we can multiply together to get $20$ .

We'll start with ${1}$ because we know that ${1}$ is a factor for every number.
We multiply ${1}\times {20}$ , to get $20$ , so ${20}$ is also a factor. We can list these factors as the outside ends of a list, leaving room in the middle for additional factors.

Now we check to see whether the next counting number, $2$ , is a factor.

Is there a whole number we can multiply by ${2}$ to get $20$ ? Yes. ${2}\times {10}=20$ . So ${2}$ and ${10}$ are another factor pair.

The next counting number is $3$ . Is there a whole number we can multiply by $3$ to get $20$ ? No. So $3$ is not a factor of $20$ .

Can we multiply ${4}$ by a whole number to get $20$ ? Yes. ${4}\times {5}=20$ . So ${4}$ and ${5}$ are a factor pair.

The next counting number is $5$ . Since $5$ already appears on the list, we now have found all of the factor pairs for $20$ .

## Multiples

Multiples are numbers that result when we multiply one whole number by another whole number. The first four multiples of ${3}$ are $3,6,9$ , and $12$ because:

Some other multiples of ${3}$ are $15,30$ and $300$ .

We can never list all of the multiples of a number. In our example, $3$ could be multiplied by an infinite number of numbers to find new multiples.

### Practice problems

The first multiple of any number is the number itself.

$7\times 1=7$ .

The list shows multiples of $4$ .

The list shows multiples of $8$ .

### Picturing multiples

The following pictures show multiples of $4$ .

The next box will include the next multiple of $4$ .

### How do factors and multiples relate?

**factors**of

**multiple**of

**multiple**of

## Practice with factors and multiples

We know that $9\times 6=54$

## Factors and multiples challenge

Factors and multiples are used when solving problems about the side lengths and areas of rectangles.

A rectangle has an area of $50$ square cm.

Mr. Trimble is putting out $36$ chocolate chip cookies for the students in his art club.

## Want to join the conversation?

- i dont understand why the multiples of 10 are not 2,5 and why the answer is 10,30,40? can you please explain(45 votes)
- The multiples are what it can create. For example, 10x2=20, 10x3=30

and the factors are what its made of. For example 10=5x2(124 votes)

- Don't you get something if you try a lot and with some mistakes ?(39 votes)
- Absolutely! Trying hard and making mistakes is one of the ways you learn. You wouldn't learn much if you just watch the video.(59 votes)

- Confuseing ;l is it or is it easy for u guys :c(8 votes)
- hey i know this comment is old, but don't give up. I'm an 11th grader starting from the bottom of math and working my way back up because my foundation wasn't strong. Don't rush math, because even if you can move on if your foundation isn't strong, it will come back to bite you in the butt.(32 votes)

- how are you supposed to anwser the question above .It doesn't make sense.(5 votes)
- Sometimes if a question doesn't make sense, it helps to click on clues or hints that might be available.

Clicking on those will mean you won't get that question correct, but at least the hints will help you understand the question (and the answer) next time it comes up.(29 votes)

- Is zero a multiple of any number, and why not?(9 votes)