Formative Instructional and Assessment Tasks
Comparing Heights
3.NBT.1– Task 2
Domain
Cluster
Standard(s)
Materials
Task
Number and Operations in Base Ten
Use place value understanding and properties of operations to perform multi-digit
arithmetic.
3.NBT.1 Use place value understanding to round whole numbers to the nearest 10 or 100.
Comparing Heights handouts, paper, pencils, calculators (optional)
Distribute copies of the Comparing Heights handout.
Read:
 Neil and Jerome were comparing their heights to see who is taller.
 Neil measured his height and said “I am 59 inches. 59 rounds to 100 so I am about
100 inches tall.”
 Jerome measured his height and said, “I am 65 inches. 65 rounds to 70 so I am about
70 inches tall. You’re taller, Neil.”
Ask: 1. What is wrong with the boys’ reasoning?
2. How could the boys correctly use rounding to compare their heights?
3. What are two examples of ways you could use rounding in your life?
Level I
Limited Performance
 Student’s response is
incorrect, incomplete,
or off task.
1.
2.
3.
4.
5.
6.
7.
8.
Rubric
Level II
Not Yet Proficient
Student does 1-2 of the following:
 Student recognizes that Neil
rounded to the nearest hundred
and Jerome rounded to the
nearest ten.
 Student states that both boys
should have rounded to the same
place for a more accurate
comparison.
 Student determines 1-2 ways that
rounding could be used in his/her
life.
Level III
Proficient in Performance
 Student recognizes that Neil rounded
to the nearest hundred and Jerome
rounded to the nearest ten.
 Student states that both boys should
have rounded to the same place for a
more accurate comparison (i.e,
round to the nearest ten since
rounding to the nearest hundred does
not lead to a realistic height).
 Student determines two ways that
rounding can be used in his/her life.
Standards for Mathematical Practice
Makes sense and perseveres in solving problems.
Reasons abstractly and quantitatively.
Constructs viable arguments and critiques the reasoning of others.
Models with mathematics.
Uses appropriate tools strategically.
Attends to precision.
Looks for and makes use of structure.
Looks for and expresses regularity in repeated reasoning.
NC DEPARTMENT OF PUBLIC INSTRUCTION
THIRD GRADE
Formative Instructional and Assessment Tasks
Comparing Heights
Neil and Jerome were comparing their heights.
Neil measured his height and said,
“I am 59 inches. 59 rounds to 100 so I am about 100 inches tall.”
Jerome measured his height and said,
“I am 65 inches. 65 rounds to 70 so I am about 70 inches tall. You’re taller, Neil.”
1. What is wrong with the boys’ reasoning?
2. How could the boys correctly use rounding to compare their heights?
3. What are two examples of ways you could use rounding in your life?
NC DEPARTMENT OF PUBLIC INSTRUCTION
THIRD GRADE