To celebrate the recent expansion to the range of SI prefixes, (for the first time in 31 years!) we challenged primary and secondary school pupils to come up with two mnemonics (how to create a mnemonic) to help remember the names of all the SI prefixes.
We are pleased to announce our winners as:
Large range: Dogs hate kissing monkeys given that primates eat zesty yuzus rather quickly
Small range: Delightful cats mostly meow nicely purring furiously and zealously yet rarely quietly
Large range: Dizzy Hot Koalas Mainly Get Tired Patiently Eating Zesty Yellow Round Quinces
Small range: Drunk Chunky Monkeys Munch Nutty Peanut Fudge After Zebras Yell Rude Questions
We are pleased to announce our runners up as:
Large range: Daydreaming Hippos Kindly Make Granola Tiramisu Pleasing Each Zebra Yelping Romantic Quotes
Small range: Do Crazy Male Magpies Need Protection From All Zebras Yelling Ridiculous Questions?
Large range: During His Kingdom's Mighty Growth, The Prince Enjoyed Zooming on Yellow, Racing Quadbikes
Small range: Dangerously Crossing Mountains Means Navigating Precisely. Find A Zipline, Yell "Rescue!" Quickly!
For submissions to be judged, they will need to be shared with NPL by an adult.
There is a worldwide agreement between all countries to measure using the International System of Units (SI). Prefixes in this system represent multiples or subdivisions, and make it easier to understand and communicate when numbers get very big or very small.
The internationally agreed SI prefixes can be combined with every SI unit of measurement, for example:
Prefix Name | Prefix Symbol | Multiplier | In practise |
milli | m | one thousandth | millimetre (mm) = 0.001 metre = 10-3 metre |
milligram (mg) = 0.001 gram = 10-3 gram | |||
kilo | k | one thousand | kilometre (km) = 1000 metre = 103 metre |
kilogram (kg) = 1000 metre = 103 metre |
For this challenge we asked participants to create two mnemonics, one for the SI prefix names for big numbers, and one for the SI prefix names for small numbers. You can see both in the chart below.
Multiplying Factor | Name (symbol) | Scientific Notation |
1 000 000 000 000 000 000 000 000 000 000 | quetta (Q) | 1030 |
1 000 000 000 000 000 000 000 000 000 | ronna (R) | 1027 |
1 000 000 000 000 000 000 000 000 | yotta (Y) | 1024 |
1 000 000 000 000 000 000 000 | zetta (Z) | 1021 |
1 000 000 000 000 000 000 | exa (E) | 1018 |
1 000 000 000 000 000 | peta (P) | 1015 |
1 000 000 000 000 | tera (T) | 1012 |
1 000 000 000 | giga (G) | 109 |
1 000 000 | mega (M) | 106 |
1 000 | kilo (k) | 103 |
100 | hecto (h) | 102 |
10 | deca (da) | 101 |
1 | 100 | |
0.1 | deci (d) | 10-1 |
0.01 | centi (c) | 10-2 |
0.001 | milli (m) | 10-3 |
0.000 001 | micro (µ) | 10-6 |
0.000 000 001 | nano (n) | 10-9 |
0.000 000 000 001 | pico (p) | 10-12 |
0.000 000 000 000 001 | femto (f) | 10-15 |
0.000 000 000 000 000 001 | atto (a) | 10-18 |
0.000 000 000 000 000 000 001 | zepto (z) | 10-21 |
0.000 000 000 000 000 000 000 001 | yocto (y) | 10-24 |
0.000 000 000 000 000 000 000 000 001 | ronto (r) | 10-27 |
0.000 000 000 000 000 000 000 000 000 001 | quecto (q) | 10-30 |
Here’s an example of mnemonics we have come up with to get you started…
Daringly | hungry | kangaroos | mock | gorillas | that | playfully | eat | zucchini | yet | rarely | quarrel |
deca | hecto | kilo | mega | giga | tera | peta | exa | zetta | yotta | ronna | quetta |
Did | centipedes | munch | my | noodles? | Please | find | all | zingy | yellow | racoons | quickly |
deci | centi | milli | micro | nano | pico | femto | atto | zepto | yocto | ronto | quecto |
A mnemonic is a system such as a pattern of letters, ideas, or associations which assists in remembering something. For example, you may have used a mnemonic before to remember the correct the order of the colours of the rainbow, or the order of the planets in space.
Richard | of | York | gave | battle | in | vain |
Red | Orange | Yellow | Green | Blue | Indigo | Violet |
My | very | easy | method | just | speeds | up | nothing |
Mercury | Venus | Earth | Mars | Jupiter | Saturn | Uranus | Neptune |
Did | centipedes | munch | my | noodles? | Please | find | all | zingy | yellow | racoons | quickly |
deci | centi | milli | micro | nano | pico | femto | atto | zepto | yocto | ronto | quecto |