Question

consolidation 6° année - section 12 3. arrondis ces nombres à la centaine près et classe-les au bon endroit. 21 876 21 863 21 847 21 811 21 851 21 800 21 811 21 900 21 847 21 863 21 851 21 876 © erpi reproduction et modifications autorisées uniquement dans les classes où le cahier décomaths 2° édition est utilisé. décomaths 5° année 6149254

Explanation:

To round a number to the nearest hundred, we look at the tens digit. If the tens digit is 0 - 4, we round down (keep the hundreds digit the same and set tens and units to 0). If the tens digit is 5 - 9, we round up (increase the hundreds digit by 1 and set tens and units to 0). Then we classify the rounded numbers.

Step 1: Round 21876 to the nearest hundred

The tens digit of 21876 is 7 (which is 5 - 9), so we round up. The hundreds digit is 8, so \(21876\approx21900\) (since \(8 + 1=9\) and tens/units become 0).

Step 2: Round 21863 to the nearest hundred

The tens digit of 21863 is 6 (5 - 9), so round up. Hundreds digit 8 becomes 9, so \(21863\approx21900\).

Step 3: Round 21847 to the nearest hundred

The tens digit of 21847 is 4 (0 - 4), so round down. Hundreds digit remains 8, so \(21847\approx21800\).

Step 4: Round 21811 to the nearest hundred

The tens digit of 21811 is 1 (0 - 4), so round down. \(21811\approx21800\).

Step 5: Round 21851 to the nearest hundred

The tens digit of 21851 is 5 (5 - 9), so round up. \(21851\approx21900\).

Now we classify:

• Numbers rounded to 21800: 21847, 21811
• Numbers rounded to 21900: 21876, 21863, 21851

Answer:

• Rounded to 21800: 21847, 21811
• Rounded to 21900: 21876, 21863, 21851