Key learning points

1. Rounding to 1 significant figure allows quick estimation with the magnitude of the estimation being close.
2. The estimation will be closer to the true answer the less rounding you do.
3. Estimating through rounding is meant to be quick and easy, taking too long defeats the purpose.

Keywords

• Estimate - A quick estimate for a calculation is obtained from using approximate values, often rounded to 1 significant figure.

• Significant figure - Significant figures are the digits in a number that contribute to the accuracy of the number. The first significant figure is the first non-zero digit.

• Overestimate - An estimate for a calculation which is greater than the exact answer.

• Underestimate - An estimate for a calculation which is less than the exact answer.

Common misconception