Respuesta :

610-187 is 423 but when you estimate it would be 400 this is your answer

⇒We have to estimate the difference

 =610 - 187

Actual Estimation=  423

⇒Estimation using Tens

 =610 - 190

 = 420

⇒Estimation using Hundreds

 =600 - 200

= 400

Correct estimation is

Estimation using Tens=420