Question

What is 6,400,000 written in scientific notation?

Answer 1

Explanation: To write a number in scientific notation, first write a decimal point in the number so that there is only one digit to the left of the decimal point.

So here, we have 6.400000 and notice that there

is only one digit to the left of the decimal point.

Next, we count the number of places the decimal point would need to move to get back to the original number, 6,400,000.

Since we would need to move the decimal point 6 places to the right, we have an exponent of positive 6.

Now scientific notation is always expressed as a power of 10.

So in this case, we will have 10 to the 6th power.

So we have
`6.400000`
`x`
`10^(6)`.

The exponent is positive because we would need to move the decimal point 6 places to the right in order to get back to our original number.

So 6,400,000 can be written in scientific notation as
`6.400000`
`x`
`10^(6)`

or just
`6.4`
`x`
`10^(6)` since we can drop zeroes at the end of a decimal.

Answer 2

B

Explanation:

6.4 × 1000000 is 6,400,000

10⁶ = 1000000