3.NBT.1 - About the Math, Learning Targets, and Rigor

Grade 3 Whole Numbers

3.NBT.A.1

Full Standard

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

 

Measurement Topic

This standard is reported on the report card in these quarters as follows:

3rd Grade Students Learning 3rd Grade Standards
Quarter 1 Quarter 2 Quarter 3 Quarter 4

Report Card Measurement Topic: Demonstrates understanding of addition and subtraction.

 

 

 

Learning Targets (I can)

  • Round to the nearest 10 (i.e. 124 rounds to 120).
  • Round to the nearest 100 (i.e. 124 rounds to 100).
  • Estimate numbers to near benchmark, friendly, or compatible numbers (i.e. 124 can be estimated to 125).
  • Explain how rounding and estimating are similar and different.
  • Determine when rounding or estimating is more useful. 

 

About the Math

Rounding is a procedure for estimating. It can be used to estimate sums, differences, products, and quotients. However, rounding is not always as accurate or efficient as estimating to friendly or compatible numbers. For example, 124 can be rounded to 120 or 100 but it may also be thought of as 125. The latter may be more efficient when adding 124 + 475. Thinking of 124 as 125 results in a quick estimate of 600. 

  • Rounding to the nearest 10

Rounding is a procedure that takes advantage of the number of numbers in a decade. It is not a rhyme such as "five and above give it a shove." Instead, there are 5 numbers that round to the same decade and five numbers that round to the next decade. For example, 60, 61, 62, 63, and 64 round to the same decade. 65, 66, 67, 68, and 69 round to the next decade.

  • Rounding to the nearest 100

Numbers can be rounded to other place values. A number can be rounded to the nearest 100 as well as the nearest 10. Rounding to the nearest 100 works much like rounding to the nearest 10. However, one uses the tens place to round to the nearest 100. There are 10 tens in a century. 5 tens that round to the same century and 5 tens that round to the next century. For example, 600, 610, 620, 630, and 640 round to 600. 650, 660, 670, 680, and 690 round to the next century.

  • Estimate numbers to near benchmark, friendly, or compatible numbers (i.e. 124 can be estimated to 125).

One can estimate with friendly numbers, benchmarks, or compatible numbers. Estimating relies on one's understanding of number relationships. Estimating a sum by rounding 193 + 177 to 190 + 180 can be challenging. Instead, we can estimate the two addends to be 200 + 200 with a sum of about 400. 

  • Explain how rounding and estimating are similar and different.

Students develop understanding of both of these in 3rd and 4th grades. Students should also understand that one is not better than the other.

  • Determine when rounding or estimating is more useful. 

As noted above, rounding is a procedure. It is a way to estimate. There are other ways to estimate. Knowing when rounding or estimating is useful is developed through routines, discussion, and mathematics experience in general. 

Essential vocabulary for this standard includes rounding and estimate. 

 

 

Progression of Standard within Grade 3

This progression informs how to develop the standard within the grade level. This progression is provided by HCPSS Elementary Mathematics.

Progression Throughout Year
Quarter 1 Quarter 2 Quarter 3 Quarter 4
  • Round to the nearest 10 (i.e. 124 rounds to 120).
  • Round to the nearest 100 (i.e. 124 rounds to 100).
  • Estimate numbers to near benchmark, friendly, or compatible numbers (i.e. 124 can be estimated to 125).
  • Explain how rounding and estimating are similar and different.
  • Determine when rounding or estimating is more useful. 
  • Use rounding and estimation before computing to determine if answers are reasonable.
  • Use rounding and estimation before computing to determine if answers are reasonable.
  • Use rounding and estimation before computing to determine if answers are reasonable.

 

Progression of this Standard Across Grades

This progression is informed by the Achieve the Core Coherence Map Links to an external site.. Information is not the complete  standard.

Progression Across Grades
Grade 2 Grade 4
Understanding of place value and bundling. (2.NBT.1) Round multi-digit numbers to any place value. (4.NBT.3)

 

 

 

 

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Tasks

These tasks can be used with small group or whole group instruction.

  • With the students, count the multiples of 10, starting with 10 and ending with 100. Chart these on the board creating a number line. Give each pair of students two 10-sided (0-9) dice. Pairs should roll the two dice and create a two-digit number and determine between which two multiples of ten does their number belong. Ask students to justify their decisions. Repeat. Then repeat with the multiples of 100 and creating 3-digit numbers and stating between which two multiples of 100 does the number fall.
  • Building on the idea above, provide students with number lines with multiples of 10. Students roll 2-digit numbers and plot the numbers to visually see which ten it is closer to. Establish that this is why the number rounds to that ten. State that when the number falls directly between, mathematicians made the decision that the number will round up. Repeat with 3-digit numbers and multiples of 100 on a number line.
  • Julie estimates that the sum of 56 + 39 is less that 100.  Do you agree?  How can you use rounding to know if she is correct? 
  • How can rounding to estimate help you determine if your answer is reasonable?  Use 178 + 185 as an example.
  • Sheila says that her number of 58 could round to 60 and 100. Is she correct? Use what you know about rounding to explain her reasoning.
  • What are 2 numbers, when added, their sum would round to 200?
  • You multiply 2 numbers and the product is almost 30. What 2 numbers could you have multiplied?
  • What value do you think the dot on the number line represents? (Show number line 100-10,000 and 1,000-5,000 with a dot marked for a number) Note: may need graphic, see Good Questions p. 47.
  • A number is rounded by tens to 120. What is the largest value the number can be? What is the smallest value the number can be?
  • Write 3 numbers that round to 500.

 

Slide-Based Tasks 

These links are HCPSS created instructional tasks. These tasks are provided in Google slides.  These tasks should be used for inspiration and resources, but instruction should start with students having the opportunity to engage with the math first (often involving physical and/or visual models) followed by discussion and explicit instruction to ensure student understanding.

 

 

Additional Tasks 

These links provide instructional ideas connected to this standard. 

 

Tasks From Print Resources

These publications have been provided for each school. They are typically stored in team closets or the media center. Check with your team leader if you cannot find them. 

Print Resources
Book Thumbnail Book Title Grade Pages
   

Groundworks - Reasoning With Numbers

 3 16-23 (Shopping Choices)
   Hands-On Standards 3-4 22 (Estimating the Sum or Difference)
 

Developing Mathematics with Base Ten

 		  

74

 
  Developing Number Concepts Book 3   99-131

Math In Practice

Teaching Grade-Three Math

 3 Module 5

 

 

 

 

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Centers

These print resources can be used during independent or center time. These resources could also be used as lesson seeds.

 

 

 

INDEPENDENT PRACTICE/HOMEWORK/ASSESSMENT

 These resource sheets can be used for independent practice, homework, or assessment. They are intended to reinforce procedures and concepts. They should not be used as a source of direct instruction or whole-group practice.

 

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Learning Targets

rubric
  • Round to the nearest 10 (i.e. 124 rounds to 120).
  • Round to the nearest 100 (i.e. 124 rounds to 100).
  • Estimate numbers to near benchmark, friendly, or compatible numbers (i.e. 124 can be estimated to 125).
  • Explain how rounding and estimating are similar and different.
  • Determine when rounding or estimating is more useful. 

 

Learning targets identify what students should be able to do.  This rubric can be applied to tasks and observations for assessment and/or grading. 

 

 

Visit the SBIR (Standards Based Instruction and Reporting) tab in Course Essentials for more information and clarification. There you will find the measurement topic crosswalk, report card comments, links to professional learning/resources and guidance.  

 

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 This course content is offered under a CC Attribution Non-Commercial Share Alike Links to an external site. license. Content in this course can be considered under this license unless otherwise noted.