Rounding & Estimating

Rounding and estimating help us simplify numbers so they are easier to work with. Instead of using exact values, we change them to nearby, simpler numbers — this makes calculations quicker and lets us check if answers are reasonable.

📍 Rounding means changing a number to the nearest 10, 100, 1000, or decimal place.

• If the digit is 5 or more, round up.
• If the digit is 4 or less, round down (keep the digit the same).

Examples:

• 47 rounded to the nearest 10 → 50
• 362 rounded to the nearest 100 → 400

🧮 Estimating means finding a quick, sensible answer by rounding the numbers first and then calculating.

Example:

198 + 403 ≈ 200 + 400 = 600 (estimated answer)

✅ Use rounding and estimating to solve problems faster and to check if your final answers make sense.