# Fractions - Change the Whole

Videos and solutions to help Grade 3 students learn how to identify a shaded fractional part in different ways depending on the designation of the whole.

Common Core Standards: 3.NF.3d, 3.NF.1, 3.NF.3a, 3.NF.3b, 3.NF.3c, 3.G.2

Related Topics:
Lesson Plans and Worksheets for Grade 3
Lesson Plans and Worksheets for all Grades
More Lessons for Grade 3
Common Core For Grade 3

New York State Common Core Math Grade 3, Module 5, Lesson 13

Lesson 13 Application Problem

Davis wants to make a picture using 9 square tiles. What fraction of the picture does 1 tile represent? Draw 3 different ways Davis could make his picture.

Lesson 13 Concept Development

Fold your index card to make 4 equal units. Shade and label the first unit.

Each part is equal to what fraction of the whole? 1 fourth.

What is the whole? The index card.
Take a black marker and trace the outside of your card to show what is the whole. 1 card is 1 whole.

Flip your index card over so you cannot see the fraction you wrote. The new whole is half of the card. Outline it with marker. Use your pencil to shade the same amount of space you shaded on the other side.
How would you label the shaded amount on this side of the card? The shaded part is 1 half. I see the whole. The shaded part is just half of that.

Changing the whole changed the unit fraction that we use to describe the shaded part.
What was 1 fourth of the whole card is 1 half of the new, smaller whole. because the new whole is different.

Try this problem shown in the video:

Kyle’s mom brought his class cake for his birthday. When she picked up the 2 cake pans at the end of the day, she said, “Wow, your friends ate 3/4 of the cake.”
Kyle said, “No mom, we ate 6/4 cakes.” Who is right?

Lesson 13 Homework

The shape represents 1 whole. Write a fraction to describe the shaded part.
The shaded part represents 1 whole. Divide 1 whole to show the same unit fraction you wrote in A.

6. Draw 4 strings, A, B, C, and D by following the directions below. String A is already done for you.
• String B is 1/3 of String A.
• String C is 1/2 of String B.
• String D is 1/3 of String C.
Extension: String E is 5 times the length of String D.

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