Sectieoverzicht

  • To check your calculations and to see how reasonable your answer is you can estimate the answer before doing the calculation. If your calculated answer is wrong, you will see straight away that it is not close to your estimate. We use the symbol \(\approx\) to show that the answer is an approximate value. 

    Example

    Sindy and TK both enter \(49\times 105\) into the calculator and get different answers. Sindy gets an answer of \( 5 040\) while TK gets an answer of \( 7 350\). Using estimation, who is closer to the actual answer?

    Round off \(49\) to \(50\) and \(105\) to \(100\).

    \(50\times 100=5 000\). So, \( 49\times 105 \approx 5 000\).

    Therefore, Sindy has the closest answer. 

    For more examples on approximating answers watch the next video.