THE HAMBURGER
the ratios of the mince and the five steps that decide the result
$1.50
SUGAR IN FRUIT
grams of natural sugar per 100 g of fresh fruit — and how much water sits beside it
$2.50
NEAPOLITAN PIZZA DOUGH
four ingredients in the proportions written into an EU regulation
Free
POUND CAKE
four equal weights — a recipe whose name is its ratio
Free
PROTEIN IN FOODS
grams per 100 g · animal and plant · and the state each one was weighed in
Free
THE CLOCK FACE
two hands, twelve numbers — how to read the time
$1.50
NUMBERS 1 TO 100
the hundred chart · primes picked out in colour
Free
MULTIPLICATION TABLE
1 to 12 · colour intensity = size of the product
Free
ROMAN NUMERALS
seven symbols · ones, tens, hundreds · years
$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