Question

7. A city has a population of 2,549,786 people.

Estimate this population to the nearest million.
Express your answer as the product of a single
digit and a power of 10.
Rounded to the nearest million, the population
is about
Written as the product of a single digit and
a power of ten, this number is
x 10​

Answer 1

1)
`2,549,786\ people \approx3,000,000\ people`

2)
`3*10^6`

Explanation:

1) To round a number to the nearest million, you must look at the digit located in the hundred thousands place. If this is greater than or equal to 5 you must round up, and if this is less than 5, you must round down.

In this case you know that the city has a population of
`2,549,786\ people`.

You can notice that the digit located in the hundred thousands place is 5, therefore, you must round up:

`2,549,786\ people \approx3,000,000\ people`

2) Scientific notation has the following form:

`a*10^n`

Where "a" must be a number from 1 to 10 but not including 10 and "n" must be an integer.

To express
`3,000,000` in Scientific notation, the decimal point must be moved 6 places to the left; therefore, the exponent will be positive.

Then:

`=3*10^6`