Rounding to the Nearest Ten and Hundred

🎯 What Will We Learn Today?

Sometimes we don't need exact numbers — an estimate is enough! Today we'll learn how to round numbers to the nearest ten and hundred.

📚 What Is Rounding?

Rounding means changing a number to a nearby "nice" number that's easier to work with. It's like saying "about how many."

📐 The Rounding Rule

If the digit is 5 or more → round UP
If the digit is 4 or less → round DOWN

🎮 Rounding to the Nearest Ten

To round to the nearest ten, look at the ones digit:

23: ones digit is 3 (less than 5) → 20

47: ones digit is 7 (5 or more) → 50

65: ones digit is 5 (5 or more) → 70

12: ones digit is 2 (less than 5) → 10

📊 Rounding to the Nearest Hundred

To round to the nearest hundred, look at the tens digit:

342: tens digit is 4 (less than 5) → 300

589: tens digit is 8 (5 or more) → 600

750: tens digit is 5 (5 or more) → 800

218: tens digit is 1 (less than 5) → 200

💡 Real-Life Rounding

A movie ticket costs $12.75 → "It costs about $13"

247 people at a concert → "There were about 250 people"

312 pages in a book → "The book has about 300 pages"

📝 Practice Problems

Round 34 to the nearest ten.

Round 476 to the nearest hundred.

Round 85 to the nearest ten.

Round 219 to the nearest hundred.

Round these to nearest ten: 18, 52, 99, 31, 75.

🎮 Play a Game!

Practice with numbers in Math Fisher — catch fish while doing math!