When you estimate,
you round the decimal up.3.9 rounds up to 4 ,5.3 rounds up to 5.4 times 5 equals 20.The actual answer is 20.67
By estimation, 3.9 turns into 4 and 5.3 turns into 5. The answer after estimation is 20 while the real answer is 20.67. Well u see by estimation we get an answer of two places right. So, real answer should also have two places.Place the decimal point after it.
1 5 1