Question

para 1 a 6, estima los productos. 1. 4×279 redondea 279 a 4×__ = 2. 9×4,720 redondea 4,720 a 9× = 3. 8×89 redondea 89 a 8× = 4. 183×4 5. 3×1,675 6. 8,210×2 para 7 a 9, haz una estimación para comprobar si la respuesta es razonable. 7. 8×578 = 4,624 redondea 578 a 8× = razonable no es razonable. 8. 3×8,230 = 2,469 redondea 8,230 a 3× = razonable no es razonable. 9. 7×289 = 2,023 redondea 289 a 7× = __ razonable no es razonable.

Explanation:

Step1: Estimate 4×279

Round 279 to 300. Then $4\times300 = 1200$.

Step2: Estimate 9×4720

Round 4720 to 5000. Then $9\times5000=45000$.

Step3: Estimate 8×89

Round 89 to 90. Then $8\times90 = 720$.

Step4: Estimate 183×4

Round 183 to 200. Then $4\times200=800$.

Step5: Estimate 3×1675

Round 1675 to 2000. Then $3\times2000 = 6000$.

Step6: Estimate 8210×2

Round 8210 to 8000. Then $2\times8000=16000$.

Step7: Check 8×578 = 4624

Round 578 to 600. Then $8\times600 = 4800$. Since 4624 is close to 4800, it is reasonable.

Step8: Check 3×8230 = 2469

Round 8230 to 8000. Then $3\times8000=24000$. Since 2469 is far from 24000, it is not reasonable.

Step9: Check 7×289 = 2023

Round 289 to 300. Then $7\times300=2100$. Since 2023 is close to 2100, it is reasonable.

Answer:

1. Round 279 to 300, $4\times300 = 1200$
2. Round 4720 to 5000, $9\times5000 = 45000$
3. Round 89 to 90, $8\times90 = 720$
4. Round 183 to 200, $4\times200 = 800$
5. Round 1675 to 2000, $3\times2000 = 6000$
6. Round 8210 to 8000, $2\times8000 = 16000$
7. Round 578 to 600, $8\times600 = 4800$, Reasonable
8. Round 8230 to 8000, $3\times8000 = 24000$, Not reasonable
9. Round 289 to 300, $7\times300 = 2100$, Reasonable