Question

Calculate the answer. How would you express it in scientific notation? `(1,632) (4.0 xx 10^4)`?

Answer 1

`"1,632" × 4.0 × 10^4 = 6.5 × 10^7`

Explanation:

Here are the three rules you need.

1. All `color (red)("non-zero digits")` are significant.
2. `color(red)("Trailing zeroes in the decimal portion")` of a number are significant.
3. In multiplication and division, `color(red)("you round the answer to have"`
   `color(red)("the same number of significant digits as the number with the")`
   `color(red)("fewest significant figures")`.

You used a period as a decimal separator in 4.0, so I assume you are using the comma as a thousands separator in 1,632.

`"1,632"` has four significant figures.

`4.0 × 10^4` has two significant figures.

The answer can have only two significant figures.

∴ `"1,632" × 4.0 × 10^4 = 6.5 × 10^7`