Whole Numbers & Place Value

Place Value

Every digit in a number has a place value — its position determines how much it is worth. In the number 3,456,789:

• 3 is in the millions place → worth 3,000,000
• 4 is in the hundred thousands place → worth 400,000
• 5 is in the ten thousands place → worth 50,000
• 6 is in the thousands place → worth 6,000
• 7 is in the hundreds place → worth 700
• 8 is in the tens place → worth 80
• 9 is in the ones place → worth 9

Rounding Numbers

To round a number, look at the digit immediately to the right of where you are rounding:

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

Example: Round 4,738 to the nearest hundred.
Look at the tens digit: 3 (less than 5) → round down → 4,700

Comparing and Ordering

To compare numbers, line them up by place value from left to right and find the first digit that differs.

Example: Order 12,405 ; 12,045 ; 12,540 from smallest to largest.
→ 12,045 < 12,405 < 12,540

Key Tips

• Be careful with zeros as place holders (e.g. 30,405 ≠ 3,045)
• Read questions carefully — 'nearest thousand' vs 'nearest ten thousand' are different
• Estimation using rounding is often a quick shortcut in multiple-choice questions