🔵Comparing & 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).
👀 See a worked example
Compare 45,210 and 45,800.
Same up to thousands; hundreds 2 < 8, so 45,210 < 45,800.
Arrange in ascending order: 3200, 980, 12000.
980, 3200, 12000 (count digits first).
🤖 Vidi's Key Points
- More digits means a bigger number.
- Same digits → compare from the left, place by place.
- Ascending = smallest first; descending = largest first.
🟢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.
👀 See a worked example
Round 63 to the nearest 10.
Ones digit 3 is 4 or less → round down to 60.
Round 348 to the nearest 100.
Tens digit 4 is 4 or less → round down to 300.
🤖 Vidi's Key Points
- Look at the digit to the right of the rounding place.
- 5 or more → round up; 4 or less → round down.
- Rounding gives a number that is simpler but close.
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