🔢 Comparing, Ordering & Rounding
More digits means a bigger number
▶ Play Door 2Comparing & Ordering Large Numbers
To compare large numbers, first count the digits — more digits means a bigger number. If the digit-count is the same, compare from the left, place by place, until one digit is bigger.
Use >, < and =. To order numbers, compare in pairs, then line them up smallest-to-largest (ascending) or largest-to-smallest (descending).
Worked example
Problem: Compare 45,210 and 45,800.
- Same up to thousands; hundreds 2 < 8, so 45,210 < 45,800.
Answer: Same up to thousands; hundreds 2 < 8, so 45,210 < 45,800.
Rounding Numbers
Rounding makes a number simpler but close to its value. Look at the digit just to the right of the place you are rounding to:
• If it is 5 or more, round up.
• If it is 4 or less, round down (keep it the same).
Example: 47 rounded to the nearest 10 → the ones digit 7 is 5+, so round up to 50.
Worked example
Problem: Round 63 to the nearest 10.
- Ones digit 3 is 4 or less → round down to 60.
Answer: Ones digit 3 is 4 or less → round down to 60.