parietal lobes 22

peacock problem 144, 144

pebbles 31, 61, 73, 102–3, 108, 109, 119–20, 124, 131, 230

perfect numbers 152

Persians 92–4, 113, 117, 149, 150

Philokleon 101–5, 107, 109, 110

phonetic signs 81, 97, 139

Pirahã 279–85

place-value system 141–6, 149, 154, 159–61, 164, 174, 184, 193

Plato 65

Plautus 114

Plofker, Kim 138

plunder 84–91, 89

Polynesia 226, 246, 248–50, 251, 252

Polynesian languages 248–50, 251, 252

Pomo 262–9, 263

positional systems 86, 97, 136, 141, 249–50

potsherds (ostraka) 108, 109, 124

pottery 272, 276

professionals, first numerate 79–80

proto-counting 12

psephoi (pebbles) 102–3, 109

Ptolemy I 92–3

punched-card machines 204–5, 208–9, 212, 213–14, 217, 220

quartz 40–1, 262

Quinhagak 255, 261

Quintilian 114

Quiringa 277–8

Rum (hand-signs for numbers) 149

rain gauge 177

ready reckoners 174

reckoning 120, 121, 127, 131

record-keeping 74, 83, 85, 86–7

Regensburg 161–2

Renaissance 117, 172, 184

Rennell, Solomon Islands 248–9

Rift Valley 33

rods, counting 5, 187, 191–5, 192, 196–9

Roman Empire 99

Arabic number symbols and 159–60

counting boards and 120–1, 127, 198, 288

finger-counting system 112–17, 113, 149, 219

‘Roman computation’ (pamphlet) 116

Roman numerals 105–7, 118, 120–1, 132–3, 161, 162, 164, 165, 182, 183, 288

Royal Gardens at Kew 179

Royal Society of London 174, 175–6

rule of three 170

Russian River people 264

Sahul 231

Salote Tupou III of Tonga, Queen 245