The purpose of this Number Talk is for students to interpret a fraction as division of the numerator by the denominator. The strategies elicited here will be helpful later in the lesson when students match division situations, expressions, and diagrams. In this activity, students have an opportunity to notice and make use of structure (MP7) because the divisor stays the same.
Launch
Display one problem.
“Give me a signal when you have an answer and can explain how you got it.”
Teacher Instructions
1 minute: quiet think time
Record answers and strategy.
Keep problems and work displayed.
Repeat with each problem.
Student Task
Find the value of each expression mentally.
35÷7
1÷7
36÷7
37÷7
Sample Response
5: I just know, 7×5=35.
71: I know that there are seven 71’s in 1.
571: I added the answers to the two previous problems.
572: I added one more 71 because 37 is one more than 36.
Activity Synthesis (Teacher Notes)
“What patterns do you notice?” (The solutions for 35÷7, 36÷7, 37÷7 increase by 71)
“If we kept increasing the dividend by 1, what would be the next whole number quotient?” (6)
Standards
Addressing
5.NF.3·Interpret a fraction as division of the numerator by the denominator (a/b = a ÷ b). Solve word problems involving division of whole numbers leading to answers in the form of fractions or mixed numbers, e.g., by using visual fraction models or equations to represent the problem. <em>For example, interpret 3/4 as the result of dividing 3 by 4, noting that 3/4 multiplied by 4 equals 3, and that when 3 wholes are shared equally among 4 people each person has a share of size 3/4. If 9 people want to share a 50-pound sack of rice equally by weight, how many pounds of rice should each person get? Between what two whole numbers does your answer lie?</em>
5.NF.B.3·Interpret a fraction as division of the numerator by the denominator <span class="math">\((a/b = a \div b)\)</span>. Solve word problems involving division of whole numbers leading to answers in the form of fractions or mixed numbers, e.g., by using visual fraction models or equations to represent the problem. <span>For example, interpret <span class="math">\(3/4\)</span> as the result of dividing <span class="math">\(3\)</span> by <span class="math">\(4\)</span>, noting that <span class="math">\(3/4\)</span> multiplied by <span class="math">\(4\)</span> equals <span class="math">\(3\)</span>, and that when <span class="math">\(3\)</span> wholes are shared equally among <span class="math">\(4\)</span> people each person has a share of size <span class="math">\(3/4\)</span>. If <span class="math">\(9\)</span> people want to share a <span class="math">\(50\)</span>-pound sack of rice equally by weight, how many pounds of rice should each person get? Between what two whole numbers does your answer lie?</span>
20 min
15 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
Division Situations
10 min
Narrative
The purpose of this Number Talk is for students to interpret a fraction as division of the numerator by the denominator. The strategies elicited here will be helpful later in the lesson when students match division situations, expressions, and diagrams. In this activity, students have an opportunity to notice and make use of structure (MP7) because the divisor stays the same.
Launch
Display one problem.
“Give me a signal when you have an answer and can explain how you got it.”
Teacher Instructions
1 minute: quiet think time
Record answers and strategy.
Keep problems and work displayed.
Repeat with each problem.
Student Task
Find the value of each expression mentally.
35÷7
1÷7
36÷7
37÷7
Sample Response
5: I just know, 7×5=35.
71: I know that there are seven 71’s in 1.
571: I added the answers to the two previous problems.
572: I added one more 71 because 37 is one more than 36.
Activity Synthesis (Teacher Notes)
“What patterns do you notice?” (The solutions for 35÷7, 36÷7, 37÷7 increase by 71)
“If we kept increasing the dividend by 1, what would be the next whole number quotient?” (6)
Standards
Addressing
5.NF.3·Interpret a fraction as division of the numerator by the denominator (a/b = a ÷ b). Solve word problems involving division of whole numbers leading to answers in the form of fractions or mixed numbers, e.g., by using visual fraction models or equations to represent the problem. <em>For example, interpret 3/4 as the result of dividing 3 by 4, noting that 3/4 multiplied by 4 equals 3, and that when 3 wholes are shared equally among 4 people each person has a share of size 3/4. If 9 people want to share a 50-pound sack of rice equally by weight, how many pounds of rice should each person get? Between what two whole numbers does your answer lie?</em>
5.NF.B.3·Interpret a fraction as division of the numerator by the denominator <span class="math">\((a/b = a \div b)\)</span>. Solve word problems involving division of whole numbers leading to answers in the form of fractions or mixed numbers, e.g., by using visual fraction models or equations to represent the problem. <span>For example, interpret <span class="math">\(3/4\)</span> as the result of dividing <span class="math">\(3\)</span> by <span class="math">\(4\)</span>, noting that <span class="math">\(3/4\)</span> multiplied by <span class="math">\(4\)</span> equals <span class="math">\(3\)</span>, and that when <span class="math">\(3\)</span> wholes are shared equally among <span class="math">\(4\)</span> people each person has a share of size <span class="math">\(3/4\)</span>. If <span class="math">\(9\)</span> people want to share a <span class="math">\(50\)</span>-pound sack of rice equally by weight, how many pounds of rice should each person get? Between what two whole numbers does your answer lie?</span>