# Math Help - Standard Index Form

1. ## Standard Index Form

1)

Astronomers measure distances in the solar system in astronomical units. (AU)
One AU is 150,000,000km.
The distance from the Sun to Pluto is 395 AU.

How many kilometres is the Sun from Pluto?
Give your answer in standard form to a sensible degree of accuracy.

2)

Write the number 4.5 x 10^-3 as an ordinary number.

3)

Find the value of (2.7 x 10^3) divided by (3.375 x 10^5)

2. Roxas? Okay, well... here we go.

1) What is the distance from the Sun to Pluto? It's 395 AU.

Now, 1 AU = 150,000,000 km
395 AU = 395 x 150,000,000 km = ?

Can you find this first in ordinary number?

2) What does "x 10^-3" mean? Do you know what does "x 10" mean?

3) Do it as follows:

$\dfrac{2.7 \times 10^3}{3.375 \times 10^5}$

Divide 2.7 by 3.375

Then, subtract the power of the 10 in the denominator from the power of 10 in the numerator.

Post what you've got so far.

3. So for the first one:

395 x 150,000,000 = 59250000000

Which is: 5.925 x 10^10?

2) that's 4.5 times 10 to the power of minus 3.