Scientific Notation · Second Year
Scientific Notation
Second Year · Very large & very small numbers · Tap NEXT to begin
Section 1 of 2
Writing in Scientific Notation
Scientific notation writes a number as $a\times 10^{n}$ where $1\le a<10$. It is for very large or very small numbers.
The rule
Big numbers: $n$ is positive. Small numbers (decimals): $n$ is negative. $a$ always has one digit before the point.
Worked example — a large number
Write $47{,}000{,}000$ in scientific notation.
Move the point so one digit stays in front: $4.7$
It moved $7$ places, and the number is big
$4.7\times 10^{7}$
Worked example — a small number
Write $0.0000591$ in scientific notation.
$5.91$, with the point moved $5$ places; the number is small
$5.91\times 10^{-5}$
Section 2 of 2
Writing it Out
Now you try
You try
Write $3.51\times 10^{7}$ without scientific notation.
Pen and paper out — try it before you reveal.
Move the point $7$ places right
$35{,}100{,}000$
$35{,}100{,}000$
You try
Write $1.2\times 10^{-4}$ without scientific notation.
Pen and paper out — try it before you reveal.
Move the point $4$ places left
$0.00012$
$0.00012$
That’s Scientific Notation.
$a\times 10^{n}$ with $1\le a<10$: positive power for big, negative for small.