GUESS THESE BY WRITING DOWN THE NUMBERS…

• How many stars do you think are in the Milky Way?• How many kilometres away do you think our sun is

from Earth?• How long do you think it would take you to fly to

Mars in a rocket?• The sun is made of mainly hydrogen and helium

gases. How heavy do you think a hydrogen atom is?• What do you think the diameter of a helium atom is?

• 200 billion = 200,000,000,000• 150 million = 150,000,000• About 220 days for a particular route.

How many hours is This?• 220 x 24 = 5280 hours = mins

• 0.00000000000000000000000167grams (3.s.f)• Hydrogen is one-quarter the weight of

a helium atom.• 0.000000000001m

316,800

• Powers of 10 • 102 = 10 × 10 = 100 • 103 = 10 × 10 × 10 = 1,000• 106 = 10 × 10 × 10 × 10 ×

10 × 10 = 1,000,000

• 1012 = 1,000,000,000,000• 5.34 × 1,000,000 • = 5.34 × 106

Compare the power to the number of zeros.

• Powers of 10 • 10-2 = = • 10-3 = = • 10-6 = = • 5.34 ×

• = 5.34 × 10-6

Write these in standard form Write these in ordinary form