Home›Lesson Plans›Mathematics›Number & Operations in Base Ten · Grade 3

Rounding & Estimation: Finding the Nearest Ten

Students place a number on a number line and let it “roll” to the closest ten — turning rounding from a memorized rule into something they can see.

Grade 3Rounding & Estimation45 minutes1 class periodGradual ReleaseExplicit teaching4 StandardsCommon Core
Start the Lesson
Lesson at a Glance

Everything you need before the bell rings

Learning Objectives

Students will be able to…

  • ✓Round two-digit numbers to the nearest ten.
  • ✓Use a number line to decide which ten is closer.
  • ✓Explain the rounding rule using the ones digit.
  • ✓Use rounding to estimate answers.
Essential Question

Is 47 closer to 40 or 50? Once you can see it on a number line, rounding stops being a rule to memorize and starts making sense.

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Lesson Phases
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Vocabulary Terms
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Standards Aligned
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Interactive Task
Model · Interactive Tool

The Number-Line Rounder

Project this and slide the number along the line. Watch it snap to the nearest ten and connect the position to the ones-digit rule.

📍 Slide the number — round to the nearest tenTry it
Number47

The Lesson · Gradual Release (I Do · We Do · You Do)

45 minutes, five moves

Tap any phase to open the teacher moves and student actions.

1

Launch — Closer to Which?

5 min

Is 47 nearer to 40 or 50?

👩‍🏫 Teacher Moves

  • Ask whether 47 is closer to 40 or 50.
  • Draw a quick number line to check.
  • Set the goal: round to the nearest ten.

🎒 Student Actions

  • Vote on 40 or 50.
  • Explain their reasoning.
  • Predict a rounding rule.
2

I Do — Round on the Line

10 min

Teacher rounds using the line.

👩‍🏫 Teacher Moves

  • Place 47 on a 40–50 number line.
  • Show it’s past the midpoint (45) → 50.
  • State the ones-digit rule (5+ rounds up).

🎒 Student Actions

  • Copy the number line.
  • Mark the midpoint at 45.
  • Round 47 to 50 and explain why.
3

We Do — Round Together

12 min

Class drives the Number-Line Rounder.

👩‍🏫 Teacher Moves

  • Use the Rounder for several numbers.
  • Test numbers just below and above 5.
  • Confirm the rule with the picture.

🎒 Student Actions

  • Call out numbers to round.
  • Predict up or down before it snaps.
  • Match the rule to the number line.
4

You Do — On Your Own

13 min

Students round and estimate.

👩‍🏫 Teacher Moves

  • Assign numbers to round to tens.
  • Add an estimation problem (round then add).
  • Include a nearest-hundred stretch.

🎒 Student Actions

  • Round numbers to the nearest ten.
  • Estimate a sum by rounding first.
  • Try rounding to the nearest hundred.
5

Close — Estimate Fast

5 min

Round to check an answer.

👩‍🏫 Teacher Moves

  • Pose a sum; estimate by rounding.
  • Compare estimate to exact.
  • Hand out the exit ticket.

🎒 Student Actions

  • Estimate a sum by rounding.
  • Say whether the exact answer is reasonable.
  • Complete the exit ticket.
Standards Alignment

Built to the standards you report on

Aligned to the Common Core State Standards for Mathematics, including the Standards for Mathematical Practice.

CCSS
3.NBT.A.1

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

CCSS
4.NBT.A.3

Use place value understanding to round multi-digit whole numbers to any place.

CCSS
4.OA.A.3

Solve multistep word problems and assess the reasonableness of answers using estimation and rounding.

SMP
MP.6

Attend to precision — knowing when an estimate is close enough.

Differentiation

One lesson, every learner

Multilingual Learners

ELL / EMERGING READERS
  • A physical number line to walk numbers along.
  • Sentence frame: “___ rounds to ___ because ___.”
  • Highlight the midpoint (5) on every line.

Support & Access

IEP / 504
  • Provide a pre-drawn number line with the tens marked.
  • Focus on rounding to tens before hundreds.
  • Use the “0–4 down, 5–9 up” rule as an anchor.

Stretch & Extend

GIFTED / EARLY FINISHERS
  • Round to the nearest hundred and thousand.
  • Estimate a multi-step problem, then check.
  • Explain why we round 5 up (a convention).
Materials

What to gather

  • 📽️Projector / board
  • 📓Math notebooks
  • 💻The Number-Line Rounder
  • 📏Printed number lines
  • ✏️Pencils
  • 🎫Exit-ticket slips
Vocabulary

Key terms — hover for a quick definition

roundreplace with a nearby, simpler numberestimatea close, rounded answernearest tenthe closest multiple of 10nearest hundredthe closest multiple of 100number linea line showing numbers in ordermidpointthe halfway mark (like 45)ones digitthe digit that decides roundingreasonableclose enough to make sense
Evaluate

Exit Ticket

Preview the three formative checks. Tap “Sample answer” to see what mastery looks like — hide them before you print for students.

QUESTION 1
Round 63 to the nearest ten. How do you know?
60 — the ones digit is 3, which is less than 5, so round down.
QUESTION 2
Round 85 to the nearest ten.
90 — the ones digit is 5, so round up.
QUESTION 3
Estimate 38 + 41 by rounding each to the nearest ten.
About 40 + 40 = 80 (the exact answer, 79, is close).

Going deeper? Estimate a shopping trip.

Give students a short “shopping list” of prices and have them round each to estimate the total before adding exactly. A printable price list is in the Math library.

Study · Flashcards

Study the key terms

Tap a card to flip it, then rate whether you knew it. Built from this lesson’s vocabulary.

🃏 Rounding & EstimationFlip
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Term
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Meaning
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Practice · Quiz

Check your understanding

A quick self-check with instant feedback, drawn from this lesson’s key terms.

📝 Rounding & EstimationQuiz
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Practice · Worksheet

Printable worksheet

A print-and-go review sheet with a built-in answer key. Tap “Show answer key” to reveal answers, or print the clean version for students.

🖨️ Rounding & EstimationPrint
Name: ________________________
Date: ____________

Part A · Write the word that matches each meaning

Word bank: estimate, midpoint, nearest hundred, nearest ten, number line, ones digit, reasonable, round
  1. close enough to make sense
  2. the halfway mark (like 45)
  3. the digit that decides rounding
  4. replace with a nearby, simpler number
  5. a line showing numbers in order
  6. a close, rounded answer
  7. the closest multiple of 10
  8. the closest multiple of 100

Part B · Show what you learned

  1. Round 63 to the nearest ten. How do you know?
  2. Round 85 to the nearest ten.
  3. Estimate 38 + 41 by rounding each to the nearest ten.
Answer key — Part A: 1) reasonable · 2) midpoint · 3) ones digit · 4) round · 5) number line · 6) estimate · 7) nearest ten · 8) nearest hundred
Part B: 1) 60 — the ones digit is 3, which is less than 5, so round down. 2) 90 — the ones digit is 5, so round up. 3) About 40 + 40 = 80 (the exact answer, 79, is close).