# Year 9

## Number and Algebra

### Very large and very small numbers

The history of our number system is well documented. We have scientific notation or standard form to represent very large and very small numbers in a convenient manner. Because many of these numbers are now used frequently, it makes sense to name them. The metric system accommodates this and computer memory uses a binary convention. Advances in technology during the twentieth century have introduced these names into general conversation. Named by a young boy in 1938, a googol is $$10^{100}$$. We talk of nano technology, with a nano being $$10^{-9}$$. We buy computers with storage in megabytes $$(2^{20})$$, gigabytes $$(2^{30})$$ and now terabytes $$(2^{40})$$.

And of course we talk of distances in space in light-years, the distance travelled by light in one year ($$365\dfrac{1}{4}$$ days).

There is a need for all students to have some knowledge of these terms, and some general understanding of their relative sizes.