Videos to help Grade 3 students learn how to explain equivalence by manipulating units and reasoning about their size.
Common Core Standards: 3.NF.3a,
Plans and Worksheets for Grade 3
Plans and Worksheets for all Grades
Lessons for Grade 3
Common Core For Grade 3
New York State Common Core Math Module 5, Grade 3, Lesson 27
The branch of a tree is 2 meters long. Monica chops the branch
for firewood. She cuts pieces that are 1/6 meter long. Draw a number line to show the total length of the branch. Partition and label each of Monica’s cuts.
a. How many pieces does Monica have altogether?
b. Write 2 equivalent fractions to describe the total length of Monica’s branch.
Each rectangle represents 1 whole. Divide each rectangle into thirds.
How can we double the number of units in the second rectangle?
We cut each third in 2.
What’s our new unit?
Repeat this process for the third rectangle.
Instead of double, triple the original
Help the students explain equivalence by looking at the different units and sizes. Also, help them to see that
the more you cut up a whole, the smaller the pieces get.
2. 8 students want to share 2 pizzas that are the same size, represented by the 2 circles below. They notice
that the first pizza is cut into 4 equal slices, and the second is cut into 8 equal slices. How can the 8
students share the pizzas equally, without breaking any of the pieces?
3. When the whole is the same, why does it take 4 copies of 1 tenth to show 2 copies of 1 fifth? Draw a
model to support your answer.
4. When the whole is the same, how many eighths does it take to make 1 fourth? Draw a model to support
Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.
You can use the free Mathway widget below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.