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3rd Math: Number & Operations Base Ten practice questions and exam guide

150 multiple-choice questions, 50 flashcards and 10 scenario simulations, written to the Common Core State Standards blueprint. Every question carries a full rationale.

Last reviewed 2026-10-26 · CoStudy · how we write and review questions

  • 210 total items
  • 150 multiple choice
  • 50 flashcards
  • 10 simulations

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About the 3rd Math: Number & Operations Base Ten exam

Common Core State Standards (CCSS) — Mathematics, Grade 3: Number & Operations in Base Ten (3.NBT.A.1-3). Public standards from corestandards.org.

CoStudy's 3rd Math: Number & Operations Base Ten bank holds 210 items. Every multiple-choice question carries a written rationale explaining why the correct answer is correct and why each distractor is tempting but wrong, and the bank includes 10 scenario-based simulations.

Free 3rd Math: Number & Operations Base Ten practice questions

A sample of 12 multiple-choice questions from the bank, with the full rationale shown.

617 + 82 = ?

  1. 599
  2. 689
  3. 709
  4. 699

Answer: D — 699

D) Correct — 7+2=9, 1+8=9, 6+0=6 → 699. B) miscarry. C) miscarry. A) missed hundreds.

Round 613 to the nearest 10.

  1. 610
  2. 620
  3. 600
  4. 605

Answer: A — 610

A) Correct — 3 < 5, round down. B) wrong direction. C) that's nearest 100. D) not multiple.

What is 5 × 90?

  1. 450
  2. 95
  3. 540
  4. 405

Answer: A — 450

5 × 9 = 45 → × 10 = 450. (B),(C),(D) wrong.

1000 − 456 = ?

  1. 544
  2. 554
  3. 534
  4. 644

Answer: A — 544

A) Correct — 1000−456=544. B/C) miscount. D) miscount hundreds.

A box has 50 candies. 6 boxes contain how many?

  1. 56
  2. 300
  3. 65
  4. 250

Answer: B — 300

6 × 50 = 300. (A),(C),(D) wrong.

761 − 289 = ?

  1. 572
  2. 482
  3. 462
  4. 472

Answer: D — 472

D) Correct — 761−289=472. B/C) miscount. A) miscount hundreds.

800 − 375 = ?

  1. 425
  2. 435
  3. 415
  4. 525

Answer: A — 425

A) Correct — 800−375=425. B/C) miscount. D) miscount hundreds.

584 + 273 = ?

  1. 867
  2. 847
  3. 857
  4. 757

Answer: C — 857

C) Correct — 4+3=7, 8+7=15, 5+2+1=8 → 857. B/A) miscarry. D) subtracted top.

Round 305 to the nearest 100.

  1. 350
  2. 400
  3. 310
  4. 300

Answer: D — 300

D) Correct — tens 0 < 5, round down. B) wrong direction. C) that's nearest 10. A) not multiple.

742 − 356 = ?

  1. 386
  2. 396
  3. 376
  4. 486

Answer: A — 386

A) Correct — 742−356=386. B/C) miscount. D) miscount hundreds.

123 + 456 = ?

  1. 479
  2. 569
  3. 589
  4. 579

Answer: D — 579

D) Correct — 3+6=9, 2+5=7, 1+4=5 → 579. B/C) miscarry. A) miscarry hundreds.

178 + 823 = ?

  1. 1011
  2. 991
  3. 901
  4. 1001

Answer: D — 1001

D) Correct — 8+3=11, 7+2+1=10, 1+8+1=10 → 1001. B) miscarry. C) missed hundreds. A) miscarry.

3rd Math: Number & Operations Base Ten flashcards

6 sample cards from the 50 in the bank.

Round 145 to the nearest 10.

150.

What is 5 × 70?

350.

Round 47 to the nearest 10.

50. (Ones digit 7 ≥ 5, round up.)

What is 845 − 327?

518.

What is 500 − 367?

133.

What is 354 + 196?

550.

Practise the full 3rd Math: Number & Operations Base Ten bank

These samples are a small slice. The full bank runs flashcards, multiple choice and timed mock exams with per-chapter progress tracking, on the web and in the iOS app.

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3rd Math: Number & Operations Base Ten — frequently asked

What is the 3rd Math: Number & Operations Base Ten exam?

Common Core State Standards (CCSS) — Mathematics, Grade 3: Number & Operations in Base Ten (3.NBT.A.1-3). Public standards from corestandards.org.

How is CoStudy’s 3rd Math: Number & Operations Base Ten bank organised?

It holds 210 items (150 multiple-choice, 50 flashcards, 10 simulations). Free samples on this page include the full rationale, with no account.

Does CoStudy replace the certifying body?

No. the certifying body owns the outline, the badge, and the sitting rules. This is independent practice with written rationales. We do not sell live items and we do not guarantee a pass.

Where do 3rd Math: Number & Operations Base Ten fees, cut scores, and pass rates live?

On the certifying body’s site. CoStudy will not invent a sitting fee or a pass rate. If a table on this page lacks a citation, treat it as unverified.

Are these real 3rd Math: Number & Operations Base Ten exam questions?

No. CoStudy does not have live items. The samples below are original practice written to the published outline, with rationales. Anyone selling “real exam dumps” is describing something you should not buy.

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