Formative Instructional and Assessment Tasks

Rounding Numbers and Products 2
4.NBT.3- Task 3
Domain / Number and Operations-Base Ten
Cluster / Generalize place value understanding for multi-digit whole numbers.
Standard(s) / 4.NBT.3 Use place value understanding to round multi-digit whole numbers to any place.
Materials / Activity sheet
Task / Rounding Numbers and Products 2
Part 1:
Mrs. Williams is playing Guess My Number with her class.
She tells the class, “When you round this number you could get the following answers:
8,000, 7,300, and 7,340. What are the possible answers for Mrs. Williams’ number?
Part 2:
Mrs. Williams then tells her class, “I want to estimate how much money we will pay for our field trip. There are 85 students going and we have to pay $19 per student. What is a reasonable estimate for the cost of the field trip? How far is the estimate from the actual answer?
Part 3:
In Part 2 round both factors and then find an estimate. Then round only the number of students. Which is a more accurate estimate? Why?
Rubric
Level I / Level II / Level III
Limited Performance
The student is unable to use strategies to find correct answers to any aspect of the task. / Not Yet Proficient
The student has between 1 and 2 errors. / Proficient in Performance
Part 1: The possible numbers are: 7,335; 7,336; 7,337; 7,338; 7,339; 7,340; 7,341; 7,342; 7,343; 7,344.
Part 2:Accurate resposnses could be one of the following: Rounding both factors: 90x20= 1,800 which is 185 away from the actual product.
Rounding only 85: 90x19 = 1,710 which is 95 away from the actual product.
Rounding only 19: 85x20= 1,700 which is 85 away from the actual product.
Part 3: Answer includes something such as, “With the numbers in the problem, the most accurate estimate is when only the number of students is rounded instead of both factors.”
Standards for Mathematical Practice
1. Makes sense and perseveres in solving problems.
2. Reasons abstractly and quantitatively.
3. Constructs viable arguments and critiques the reasoning of others.
4. Models with mathematics.
5. Uses appropriate tools strategically.
6. Attends to precision.
7. Looks for and makes use of structure.
8. Looks for and expresses regularity in repeated reasoning

Rounding Numbers and Products 2

Part 1:

Mrs. Williams is playing Guess My Number with her class.

She tells the class, “When you round this number you could get the following answers:

8,000, 7,300, and 7,340. What are the possible answers for Mrs. Williams’ number?

Part 2:
Mrs. Williams then tells her class, “I want to estimate how much money we will pay for our field trip. There are 85 students going and we have to pay $19 per student. What is a reasonable estimate for the cost of the field trip? How far is the estimate from the actual answer?

Part 3:

In Part 2 round both factors and then find an estimate. Then round only the number of students. Which is a more accurate estimate? Why?

NC DEPARTMENT OF PUBLIC INSTRUCTION FOURTH GRADE