Not all roles available for this page.
Sign in to view assessments and invite other educators
Sign in using your existing Kendall Hunt account. If you don’t have one, create an educator account.
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
The purpose of this activity is for students to reason about the size of quotients, involving a unit fraction and a whole number, by carefully analyzing the relative sizes of the dividend and divisor rather than finding the value of the expressions. As students work, listen for the language they use to explain why they think the value of an expression is greater than or less than 1. Highlight the language during the Activity Synthesis. When students explain to each other how they decided whether a quotient is greater than 1 or less than 1 they construct viable arguments (MP3).
This activity uses MLR1 Stronger and Clearer Each Time. Advances: Reading, Writing.
Without calculating the value of the expressions, write each expression under the correct category.
The value of the expression is less than 1.
The value of the expression is greater than 1.
The purpose of this activity is for students to order the quotients from the previous activity from least to greatest, without calculating. The quotients of a whole number by a unit fraction have the same dividend so students reason that the expression with the smallest unit fraction divisor represents the largest quotient. In the same way, the quotients of a unit fraction by a whole number all have the same divisor so the expression with the largest unit fraction dividend is the largest.
Display:
“What do we know about the value of this expression if the number in the box is a whole number?” (It is going to be greater than 25. It is going to be a multiple of 25.)
Display:
“What do we know about the value of this expression if the number in the box is a whole number?” (It is going to be a unit fraction. The denominator is going to be a multiple of 25.)
We learned to divide with whole numbers and unit fractions. First, we used diagrams to solve problems involving division of a unit fraction by whole numbers.
Example:
Diagram A shows equals . We find the size of one part if is split into 4 equal parts.
Then we noticed the relationship between division and multiplication.
For Diagram A, we know that because .
Next, we used diagrams to solve problems involving division of whole numbers by unit fractions. We also wrote equations to represent these problems.
Example:
Diagram B shows that if a strip of paper 2 feet long is cut into foot pieces, there will be 12 pieces. Therefore, because we are finding how many -size pieces are the same length as 2.
Finally, we noticed patterns when dividing whole numbers and unit fractions.
We noticed whole numbers divided by unit fractions were greater than 1.
Example:
The value of is greater than 1. The number of -size pieces with length 12 (or any whole number) is greater than 1.We also noticed unit fractions divided by whole numbers were less than 1.
Example:
The value of is less than 1. When a whole number less than 1 is divided into many pieces, each piece is less than 1.