Using Units Flashcards

All 7 cards in this deck

What does the prefix milli mean?

One thousandth, $10^{-3}$; e.g. $1\ \text{mm} = 10^{-3}\ \text{m}$.

What does the prefix micro ($\mu$) mean?

One millionth, $10^{-6}$; e.g. $1\ \mu\text{m} = 10^{-6}\ \text{m}$.

What do the prefixes nano and pico mean?

Nano $= 10^{-9}$ and pico $= 10^{-12}$.

What is standard form?

A number written as $A \times 10^{n}$, where $1 \le A < 10$; e.g. $0.0077 = 7.7 \times 10^{-3}$.

What are the steps to convert a length in millimetres into micrometres?

e.g. $0.05\ \text{mm}$

1. Recall $1\ \text{mm} = 1000\ \mu\text{m}$.
2. Multiply by 1000: $0.05 \times 1000 = 50\ \mu\text{m}$.

When is it appropriate to use an estimate of size or number?

When an exact measurement is not possible or not needed — e.g. estimating cell numbers in a field of view, or checking a calculated answer is sensible.

True or false? $1\ \mu\text{m} = 1000\ \text{nm}$.

True. A micrometre is $10^{-6}\ \text{m}$ and a nanometre is $10^{-9}\ \text{m}$.