Grades Grade 3 Base Ten OperationsRounding to the Nearest 10 or 100

Rounding to the Nearest 10 or 100

🔢 Base Ten Operations

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Rounding to the Nearest 10 or 100

Rounding finds the closest "round" number — useful for estimating!

Rounding replaces a number with a close, simpler number. We round to the nearest 10 or the nearest 100. A rounded number is an estimate — it is close but not always exact.

Rules for rounding to the nearest 10:

1Look at the ONES digit

2If the ones digit is 0–4, round DOWN (keep the tens digit the same)

3If the ones digit is 5–9, round UP (increase the tens digit by 1)

4Replace the ones digit with 0

📍Rounding to the nearest 10

43 → ones digit is 3 (less than 5) → round DOWN → 40
67 → ones digit is 7 (5 or more)  → round UP   → 70
85 → ones digit is 5 (5 or more)  → round UP   → 90

Rules for rounding to the nearest 100:

1Look at the TENS digit

2If the tens digit is 0–4, round DOWN (keep the hundreds digit)

3If the tens digit is 5–9, round UP (increase the hundreds digit by 1)

4Replace both the tens and ones digits with 0

📍Rounding to the nearest 100

234 → tens digit is 3 → round DOWN → 200
678 → tens digit is 7 → round UP   → 700
350 → tens digit is 5 → round UP   → 400

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Remember This!

Picture a number line! The number is closer to whichever "round" number it sits nearest to. If it is exactly in the middle (like 250), we always round UP.

✏️ Try It!

Round 473 to the nearest 100.

Practice with CalcVerse

🎯Rounding & Estimation

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