# Units and currencies

## Example 1: Units

Let us create a basic question with units:

We need to enable the *units* and *prefixes* we want to use in *Input options* > *Input syntax*. You can check only those units and prefixes you are interested in or use the *All* tab.

The algorithm is very simple:

Note that since the corresponding units and prefixes are selected, the units are highlighted in blue. `s`

and `l`

are also highlighted because there exist the units second and liter, but since they are preceded by *#*, they are interpreted as a variable name.

Finally, you can also select the *Match unit of measure* validation option to force the student answer to be expressed in meters.

## Units

### Basic units of the SI

Magnitude | Name | Symbol |
---|---|---|

Length | meter | m |

Mass | kilogram | kg |

Time | second | s |

Electric current | amper | A |

Thermodynamic temperature | kelvin | K |

Quantity of substance | mol | mol |

Luminous intensity | candela | cd |

### Units derived from SI

Magnitude | Name | Symbol |
---|---|---|

Plane angle | radian | rad |

Solid angle | steradian | sr |

Frequency | hertz | Hz |

Force | newton | N |

Pressure, strain | pascal | Pa |

Energy, work, quantity of heat | joule | J |

Power, radiant flux | watt | W |

Electric potential difference, electromotive force | volt | V |

Capacitance | farad | F |

Electrical resistance | ohm | |

Electrical charge | coulomb | C |

Electrical conductivity | siemens | S |

Magnetic flux | weber | Wb |

Magnetic flux density | tesla | T |

Inductance | henry | H |

Luminous flux | lumen | lm |

Illuminance | lux | lx |

Radioactivity | becquerel | Bq |

Absorbed dose | gray | Gy |

Equivalent dose | sievert | Sv |

Catalytic activity | katal | Kat |

### Units from other systems

Magnitude | Name | Symbol |
---|---|---|

Time | hour | h |

Time | minute | min |

Volume | liter | l |

Pressure, strain | bar | b |

## Metric prefixes

Text | Symbol | Factor | Power |
---|---|---|---|

exa | E | ||

peta | P | ||

tera | T | ||

giga | G | ||

mega | M | ||

kilo | k | ||

hecto | h | ||

deca | da | ||

deci | d | ||

centi | c | ||

mili | m | ||

micro | |||

nano | n | ||

pico | p | ||

femto | f | ||

atto | a |

## Example 2: Currencies

Let us create a basic question with currencies:

As you have seen in the example involving units, you need to enable the currencies in *Input options* > *Input syntax*. Notice all currencies can be selected with only one box.

The algorithm is very simple. Notice that if you want to make an algorithm for a question with currencies, you must use the corresponding CalcMe symbol for them under *Units of measure* tab.

To conclude, currencies are similar to physical units and we have to take into account:

- You can do basic arithmetic with currencies
- ... except you can not
`convert()`

between them. - Students can write the currency symbol at left ($12) or at right (34€). Both styles will be graded as correct.
- Students must type the currency symbol using their keyboard. The toolbar for the answer doesn't have any currency symbols. So please ensure that students have the symbol on their keyboard! Alternatively, provide it in the question wording for them to copy & paste.

## Currencies

See below a list of the currently accepted currencies:

Symbol | Name |
---|---|

BTC | Bitcoin |

$ | Dollar |

€ | Euro |

Fr | Franc |

kr | Koruna/Krona/Krone |

£ | Pound |

₽ | Ruble |

₹ | Rupee |

₩ | Won |

¥ | Yen/Yuan |