Math · Stage 3
Round numbers to the nearest 10 and 100 and estimate to check answers
Hop to the closest signpost — 47 → 50, 372 → 400 — then round first to estimate and spot answers that can't be right.
✦ Math📘 Stage 3 · S3⏱ ~11 min🧒 Ages 7–8★ Free to start
I can round numbers to the nearest 10 and 100 and estimate to check.
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Kavi's Rounded Guess 🌰
Kavi scoops up 47 acorns, then spots a pile of 372 more 🌰. "I don't need the exact count to guess the total," he hoots. "47 is nearest 50, and 372 is nearest 400 — so it's about 450!" A friend blurts "it's 45!" Kavi grins: "My estimate says near 450 — so 45 is far too small!"
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What your child will learn
1Hop to the nearest signpostThe tens are signposts: 0, 10, 20, 30…. Every number sits between two of them. Rounding means hop to the closest signpost. Tap Hop +10 to travel ten by ten.
2Let one digit decideFor the nearest 10, look at the ones digit. For the nearest 100, look at the tens digit. Build 372: hundreds 3, tens 7, ones 2.
3The hundred signpostsNow the big signposts are the hundreds: 0, 100, 200, 300, 400. Tap Hop +100 to travel signpost to signpost and find the hundred each number is closest to.
4Round first, then addHere's why rounding is so handy. To estimate 372 + 47, round each to a friendly number: 372 → 400 (nearest hundred) and 47 → 50 (nearest ten). Tap Step → to build the easy sum 400 + 50.
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A peek inside
Round 47 to the nearest 10.
ones digit is 7 (5 or more) → round up
Try this at home: Round to the nearest 10: 47 → __ · 23 → __ · 85 → __
Ready to play and learn?
Start the free interactive lesson, or print the handout for screen-free play.
Part of Math · Stage 3 · S3 on KAVI Academy — a secular, whole-child learning platform for ages 5–12.