Grade 3 · Number & Operations in Base Ten · MAT-03-NBT-001
Round Whole Numbers to the Nearest 10
Represent round whole numbers to the nearest 10 with words, symbols, diagrams, or models appropriate to Grade 3.
Learning objectives
What you should be able to do
- Represent round whole numbers to the nearest 10 with words, symbols, diagrams, or models appropriate to Grade 3.
- Solve problems involving round whole numbers to the nearest 10 accurately and explain why the method works.
- Check results for reasonableness using a second representation, inverse relationship, benchmark, or property when appropriate.
Prerequisite check
Make sure the foundation is ready.
Checks conceptual readiness before new Grade 3 reasoning.
Checks whether prior skills are available for use, not only recalled by name.
Learn
Build the idea from meaning, not memorization.
Meaning of Round Whole Numbers to the Nearest 10
Rounding to the nearest ten replaces a number with the closest multiple of 10.
A reliable reasoning strategy
Locate the two neighboring tens and compare distances; a ones digit of 5 or more rounds to the higher ten.
Representations that should agree
A number line shows rounding as a nearest-distance decision, not a digit trick. A correct model, equation, verbal explanation, or diagram should preserve the same quantities and relationships.
How to check the result
Check whether the answer fits the quantities, units, and structure of the problem. Use a second representation or inverse relationship when available, and explain what would make an answer unreasonable.
Interactive math lab
Change it. See what stays true.
Number Line Explorer
Move along the number line.
4 is one less. 5 and 6 is one more.
- build a model
- change one quantity
- predict before calculating
- explain why the result changes
Worked examples
Twenty different ways to see the concept work.
Round 137 to the nearest 10.
137 is closest to 140.Compare the number with the two neighboring multiples of 10.
Round 174 to the nearest 10.
174 is closest to 170.Compare the number with the two neighboring multiples of 10.
Round 211 to the nearest 10.
211 is closest to 210.Compare the number with the two neighboring multiples of 10.
Round 248 to the nearest 10.
248 is closest to 250.Compare the number with the two neighboring multiples of 10.
Round 285 to the nearest 10.
285 is closest to 290.Compare the number with the two neighboring multiples of 10.
Round 322 to the nearest 10.
322 is closest to 320.Compare the number with the two neighboring multiples of 10.
Round 359 to the nearest 10.
359 is closest to 360.Compare the number with the two neighboring multiples of 10.
Round 396 to the nearest 10.
396 is closest to 400.Compare the number with the two neighboring multiples of 10.
Round 433 to the nearest 10.
433 is closest to 430.Compare the number with the two neighboring multiples of 10.
Round 470 to the nearest 10.
470 is closest to 470.Compare the number with the two neighboring multiples of 10.
Round 507 to the nearest 10.
507 is closest to 510.Compare the number with the two neighboring multiples of 10.
Round 544 to the nearest 10.
544 is closest to 540.Compare the number with the two neighboring multiples of 10.
Round 581 to the nearest 10.
581 is closest to 580.Compare the number with the two neighboring multiples of 10.
Round 618 to the nearest 10.
618 is closest to 620.Compare the number with the two neighboring multiples of 10.
Round 655 to the nearest 10.
655 is closest to 660.Compare the number with the two neighboring multiples of 10.
Round 692 to the nearest 10.
692 is closest to 690.Compare the number with the two neighboring multiples of 10.
Round 729 to the nearest 10.
729 is closest to 730.Compare the number with the two neighboring multiples of 10.
Round 766 to the nearest 10.
766 is closest to 770.Compare the number with the two neighboring multiples of 10.
Round 803 to the nearest 10.
803 is closest to 800.Compare the number with the two neighboring multiples of 10.
Round 840 to the nearest 10.
840 is closest to 840.Compare the number with the two neighboring multiples of 10.
Practice
Guided practice with hints
01Round 397 to the nearest 10.
Hint: Locate the two neighboring tens and compare distances; a ones digit of 5 or more rounds to the higher ten.
Answer: 400
02Round 434 to the nearest 10.
Hint: Locate the two neighboring tens and compare distances; a ones digit of 5 or more rounds to the higher ten.
Answer: 430
03Round 471 to the nearest 10.
Hint: Locate the two neighboring tens and compare distances; a ones digit of 5 or more rounds to the higher ten.
Answer: 470
04Round 508 to the nearest 10.
Hint: Locate the two neighboring tens and compare distances; a ones digit of 5 or more rounds to the higher ten.
Answer: 510
05Round 545 to the nearest 10.
Hint: Locate the two neighboring tens and compare distances; a ones digit of 5 or more rounds to the higher ten.
Answer: 550
06Round 582 to the nearest 10.
Hint: Locate the two neighboring tens and compare distances; a ones digit of 5 or more rounds to the higher ten.
Answer: 580
Practice
Independent practice
01Round 287 to the nearest 10.
Answer: 290
02Round 324 to the nearest 10.
Answer: 320
03Round 361 to the nearest 10.
Answer: 360
04Round 398 to the nearest 10.
Answer: 400
05Round 435 to the nearest 10.
Answer: 440
06Round 472 to the nearest 10.
Answer: 470
07Round 509 to the nearest 10.
Answer: 510
08Round 546 to the nearest 10.
Answer: 550
Common mistakes
Learn to catch the error, not just the answer.
Identify the lower and upper tens before choosing the nearer one.
Reconnect the answer to round whole numbers to the nearest 10 and verify that the model, calculation, and label describe the same quantity.
Applications & challenge
Use the idea beyond a single exercise.
Applications
- Estimate totals, distances, and quantities quickly.
- Use round whole numbers to the nearest 10 to interpret or solve a Grade 3 situation with quantities, diagrams, measurements, or data.
Challenge problems
Round 177 to the nearest 10.
180
Round 214 to the nearest 10.
210
Round 251 to the nearest 10.
250
Round 288 to the nearest 10.
290
Flashcards
Retrieve it from memory.
Flashcards
Card 1 of 4
Game mode
Round Whole Numbers to the Nearest 10 Challenge
Solve and explain Grade 3 problems involving round whole numbers to the nearest 10 without relying on answer guessing.
Practice
Mastery check
01Round 917 to the nearest 10.
Answer: 920
02Round 104 to the nearest 10.
Answer: 100
03Round 141 to the nearest 10.
Answer: 140
04Round 178 to the nearest 10.
Answer: 180
05Round 215 to the nearest 10.
Answer: 220
06Round 252 to the nearest 10.
Answer: 250
07Round 289 to the nearest 10.
Answer: 290
08Round 326 to the nearest 10.
Answer: 330
Terminology
Words to know
- round
- Replace a number with a nearby value at a chosen place.
- multiple of 10
- A whole number ending in zero.
Continue learning
Connected concepts
Curriculum references
Standards and instructional references
California Common Core State Standards for Mathematics — Grade 3, 3.NBT.1
Primary standards alignment for Round Whole Numbers to the Nearest 10.2023 Mathematics Framework for California Public Schools
Instructional emphasis on reasoning, representations, problem solving, and equitable access.