Significant Figures
When ever we use numbers to talk about distances and amounts we often replace digits with zeroes or completely ignore numbers. Consider the following examples:
- A very rich man might have $76 301 080 980.43 (you might just say he has 76 billion dollars)
- A cell might weigh 0.0000350980230109 kilograms (you might just say 0.000035kg)
When we do this, we are choosing the most significant figures. In the two examples above we selected the 2 most significant numbers.
Scientific Notation
Some numbers are so big, it becomes difficult to write them down. This is when scientific notation comes in handy. Consider the following examples:
- the total weight of cellular protein is \(7 \times 10{−10}\text{ g}
- the distance from the Earth to the sun is \(1.496 \times 10{9}\,\text{ km}\)
- Perform the operation \(1200000^2\) on your calculator. If your calculator is restricted to 10-digit numbers, it should give you a solution in scientific notation (since it can’t fit on the screen).