Mystery Bureau › Grade 3 standards › 3.NBT.A.2
📘 Common Core · 3.NBT.A.2 · Grade 3
Three digits is where subtraction stops forgiving guesswork. Borrowing across a zero — 705 minus 208 — is the case that separates students who understand place value from students following a remembered procedure. The standard allows both strategies and algorithms, and for numbers like 640 minus 175, breaking the number apart is often faster than the column method.
Quoted verbatim from the Common Core State Standards for Mathematics. Nothing here is paraphrased.
| 3.NBT.A.2 | Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction. |
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In plain English: Add and subtract within 1,000 fluently, using place-value strategies and algorithms.
Each one runs in the browser with no account and nothing stored. Five questions apiece.
Real output from the activities above — not written for this page, drawn from the same pools a student gets. The numbers are rebuilt on every attempt.
| 706 − 291 = ? | 415 |
| 889 − 174 = ? | 715 |
| 324 − 241 = ? | 83 |
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