Astronomy has really big numbers
Distance between Earth and Sun meters kilometers This is the closest star.
Distance To Next Closest Star Alpha Centauri kilometers Or meters Too big. Mind explosion.
What’s a better way? × km Or light years
Scientific Notation A number is written in two parts: 1.Just the digits (with the decimal point placed after the first digit), 2.× 10 to a power Example: 2.75 x 10 3
x 10 3 = ???????? × 10 to a power puts the decimal point back where it should be (i.e. it shows how many places to move the decimal point). Examples: 2.75 x 10 3 =
Another Example
How to do it Step 1 To figure out the power of 10, think –"how many places do I move the decimal point?"
How to do it Step 2 If the number is 1 or greater –the decimal place has to move to the left – the power of 10 will be positive. If the number is smaller than 1 –then decimal place has to move to the right –the power of 10 will be negative:
Example would be written as 5.5 × Because = 5.5 × = 5.5 × 10 -3
Why not just write the number? Scientific Notation is used for numbers that are HUGE or tiny For example it is easier to write (and read) 1.3 × Than
So what do you think? The distance from the earth to the sun meters kilometers or 1.50 x m Which one is easier to read?