STUDENT
TEACHER

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STUDENT
TEACHER

Act 1

STUDENT
TEACHER

QUICK LINKS


FILES


STUDENT
TEACHER

Act 1

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Greatest Common Factor (GCF)

This 3 Act Task helps students reimagine GCF through composite shapes. The puzzle asks students to break up two composite shapes into their component shapes of triangles, squares, and semicircles to find the GCF of the two shapes. The rest of the lesson helps students visualize factors by imagining splitting up candy among friends.

ACT 1

Inspiring Interest

ENGAGE
1.
Before presenting the Act 1 video, ask students to consider the following questions as they watch:
“What do you notice? What do you wonder?”
“Is there anything that sticks out?”
“Is there anything that reminds you of something else?”
“What are you curious to know?”

2.
Present the Act 1 video.

3.
After presenting the Act 1 video, allow students to share their initial thoughts.

4.
Replay the Act 1 video and continue with the following questions:
“What do you think is the solution to the puzzle?”
“Are there any predictions you’d automatically rule out? Why or why not?”
“What additional information would help you make a more confident prediction?”

5.
After allowing students to share their initial predictions, proceed to Act 2.

ACT 2

Stimulating Thinking

ENGAGE
1.
Before presenting the Act 2 video, ask students to be on the lookout for new information that will help them refine their predictions.

2.
Present the Act 2 video.

3.
After presenting the Act 2 video, prompt students to consider the following questions:
“How does this new information affect your initial prediction?”
“Are there any changes you’d like to make? Why or why not?”

4.
Give students time to finalize their predictions.

5.
Continue with the following questions:
“What is your final prediction?”
“What is the reasoning behind your prediction?”
“How does your prediction and reasoning compare to others in the class?”

6.
After allowing students to share their final predictions, proceed to Act 3.

ACT 3

Illuminating Teacher Moves

ENGAGE
1.
Before presenting the Act 3 video, celebrate the process! 🥳
Remind students that regardless of whether or not their prediction turns out to be correct, everyone has already successfully completed the activity by putting their existing knowledge to work and engaging in critical thinking.

2.
Present the Act 3 video.

3.
After presenting the Act 3 video, take some time to validate students’ reactions.
Irrespective of whether or not their prediction is correct, students may experience a variety of emotions including, but not limited to:
Encouragement, joy, curiosity, excitement
Discouragement, frustration, confusion, and apathy
Take some time to reflect on who your students are and how you can leverage their unique personalities to guide their emotions to a place of awareness and appreciation for the learning that is taking place.
EXPLORE
EXPLAIN
ELABORATE
EVALUATE

Greatest Common Factor (GCF)

CALCULATOR

GCF Calculator

Find the greatest common factor, or GCF, ofand.

Step 1. Remember what a factor is.

A factor is a number that fits evenly into another number.

Step 4. Find the greatest common factor.

This is the largest factor the two numbers have in common.
Factors of
Factors of
So, the greatest common factor, or GCF, is .
We have some questions for you! Help us out through this
INTRO
A factor is a number that fits evenly into a given number.
Factors always come in pairs consisting of the factor and the number of times it fits evenly into the given number.
It's like we're dividing candy up - the factors are the number of people we can divide the candy equally among and the number of pieces each person gets.
Click on the buttons below to see the factors and factor pairs of :
Factors of
:
fits evenly into times.
The Greatest Common Factor (GCF) is the largest factor two or more numbers have in common.
Factors of
Factors of
When we organize the factors from least to greatest, we can easily see that the GCF of and is .

Greatest Common Divisor (GCD)

GCD is the same thing as GCF. It tells us the largest number two or more numbers can be evenly divided by.
Check out our
Calculator
or explore our
Lesson
and
Practice
sections to learn more about how to find the greatest common factor and test your understanding.

You can also use the Quick Links menu on the left to jump to a section of your choice.

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KEY STEPS

How to Find the GCF

Step 1. Remember what a factor is.

A factor is a number that fits evenly into another number.

Step 2. Find the factors of the first number.

We’re looking for every number that fits evenly into the first number.

Step 3. Find the factors of the second number.

We’re looking for every number that fits evenly into the second number.

Step 4. Find the greatest common factor.

This is the largest factor the two numbers have in common.
LESSON
Finding the GCF
PRACTICE
Finding the GCF
CONCLUSION
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