Subjectastronomy1body and care2code2drinks15food5language0maths0music2science0signals2sport3units2vehicles4
PHASES OF THE MOON
eight phases · a full cycle of 29.53 days
$1.50
MORSE CODE
26 letters and 10 digits · dot, dash
Free
PHONETIC ALPHABET
the ICAO standard · for radio and telephone
$2.50
IMPERIAL UNITS
convert in your head · without a calculator
Free
PAPER SIZES
the A series · from A0 to A6
$1.50