3.NBT.1

Standard

Use place value understanding to round whole numbers to the nearest 10 or 100.


Student language:

    • "I can round numbers to the nearest ten or 100."

Explanation

About the Math, Learning Targets, and Rigor

This standard refers to place value understanding, which extends beyond an algorithm or procedure for rounding.

Students should have numerous experiences using a number line and a hundreds chart as tools to support their work with rounding. Students learn when and why to round numbers. They identify possible answers and a halfway point. Then they narrow where the given number falls between the possible answers. They also understand that by convention if a number is exactly at the halfway point of the two possible answers, at this level the number is rounded up.


Note: The strategies for rounding are valuable for estimating, justifying and predicting the reasonableness of solutions in problem-solving.

Common Misconception

The use of terms like “round up” and “round down” confuses many students. For example, the number 37 would round to 40 or they say it “rounds up”. The digit in the tens place is changed from 3 to 4 (rounds up). This misconception is what causes the problem when applied to rounding down.

The number 32 should be rounded (down) to 30, but using the logic mentioned for rounding up, some students may look at the digit in the tens place and take it to the previous number, resulting in the incorrect value of 20.

To remedy this misconception, students need to use a number line to visualize the placement of the number and/or ask questions such as: “What tens are 32 between and which one is it closer to?”

**Developing the understanding of the WHY behind rounding, what the answer choices are, using place value understanding to round numbers, rather than relying on rounding rhymes e.g. Find your number, look next door, five or greater add one more, five or more raise the score, and so on, can alleviate much of the misconception and confusion related to rounding.**

Resources

Videos



EngageNY Lessons


Extra Practice


Released Assessment Questions

PARCC

3.NBT.1

Use place value understanding to round whole numbers to the nearest 10 or 100.


Integrated Standards

3.Int.1

Given a two-step problem situation with the four operations, round the values in the problem, then use the rounded values to produce an approximate solution.

(Content Scope: 3.OA.8, 3.NBT.1, 3.NBT.2, 3.NBT.3)

    • Tasks must be aligned to the first standard and 1 or more of the subsequent standards listed in the content scope.
    • Tasks do not require computations beyond the grade 3 expectations.
    • Tasks do not require a student to write a single equation with a letter standing for the unknown quantity in a two-step problem, and then solve that equation.
    • Tasks may require students to write an equation as part of their work to find a solution, but students are not required to use a letter for the unknown.
    • Addition, subtraction, multiplication and division situations in these problems may involve any of the basic situation types with unknowns in various positions (see CCSSM, Table 1,Common addition and subtraction situations, p. 88; CCSSM, Table 2, Common multiplication and division situations, p. 89; and the Progression document for the OA Progression).

Performance Indicators: 3.Int.1

Level 5: Exceeds Expectations

Solves two-step unscaffolded word problems using the four operations, including rounding where appropriate, in which the unknown is in a variety of positions. Both values for each operation performed is substantial (towards the upper limits as defined by the standard assessed).

Level 4: Meets Expectations

Solves two-step scaffolded word problems using the four operations in which the unknown is in a variety of positions. One of the values for each operation performed is substantial (towards the upper limits as defined by the standard assessed).