131 De³³⁶ venditione librarum cum queritur pretium rotulorum

Item rotuli \({1 \over 9}\),\({3 \over 5}\) 11, hoc est \({1~~3~~\phantom{1}11 \over 9~~5~~100}\) unius cantarii, venduntur pro denariis \({1~~\phantom{1}3 \over 2~~10}\) 19; quantum valent³³⁷ libre \({1 \over 10}\) \({1 \over 9}\) \({3 \over 4}\) 7, hoc est \({1~~1~~3~~\phantom{1}7\phantom{8} \over 10~~9~~4~~158}\) unius cantarii? Describe questionem et multiplica 11 que sunt super 100 per 5 et adde 3, que per 9 et adde multiplicationem de 1 quod est super 9 in 5: erunt 527 que pone super \({1~~3~~\phantom{1}11 \over 9~~5~~100}\). 132 Item multiplica 19 per 10 et adde 3, que per 2 et adde 1; erunt 387, que pone super \({1~~3 \over 2~~10}\) 19. Et adhuc

② 387 527 d. can. \({1~~3 \over 2~~10}\) 19 \({1~~3~~\phantom{1}11 \over 9~~5~~100}\) pensa ③ est 2 per 7 2866 \({0~~7~~10~~21~~25 \over 2~~8~~17~~31~~79} 8\) \({1~~1~~3~~7 \over 10~~9~~4~~158}\)

³³⁸ multiplica 7 que sunt super 158 per 4 et per reliquos, ut superius³³⁹; erunt³⁴⁰ 2866. 133 Et multiplica 387 per 2866; erunt 1109142, que cum debeas multiplicare per 5 et per 9 et per 100 que sunt sub virgula sub 527³⁴¹, et dividere summam per regulam de 527, que est \({\phantom{1}1~~\phantom{1}0 \over 17~~31}\)³⁴², et per reliquos numeros qui sunt sub virgulis reliquorum duorum numerorum, relinquatur³⁴³ quod non multiplicetur per 9 nec per 100³⁴⁴; 134 et relinquetur quod non dividetur per 9 nec per 10 que sunt in virgula sub 2866, nec per 10 que sunt sub virgula sub 387. Ergo multiplicabis [F:40r] 1109142 tantum per 5³⁴⁵; erunt 5545710, que divides³⁴⁶ per \({1~~0~~\phantom{1}0\phantom{1}~~\phantom{1}0\phantom{1} \over 2~~4~~158~~527}\), hoc est per \({1~~0~~\phantom{1}0~~\phantom{1}0~~\phantom{1}0 \over 2~~8~~17~~31~~79}\): exibunt denarii \({0~~7~~10~~21~~25 \over 2~~8~~17~~31~~79}\)³⁴⁷ 8

135 Item rotuli 11 gerovi valent in Alexandria karatos 17³⁴⁸; quantum

kar. ℞ for. 17 143   \({5 \over 6}\) 23 pensa est ⓪ per 9   \({\phantom{1}5~~\phantom{1}5 \over 11~~13}\) 6 9

³⁴⁹ valent³⁵⁰ rotuli 9 forfori? Quia rotuli 11 et rotuli 9 non sunt unius ponderis, vel de rotulis 11 gerovi facies rotulos forfori, vel de³⁵¹ rotulis 9 forfori facies rotulos gerovi, ut fiant ambo³⁵² vel forfori vel gerovi. Sed quia de³⁵³ rotulis gerovinis 11 levius potes facere rotulos forfori quam de rotulis 9 forfori facere gerovi³⁵⁴, ideo quia unusquisque rotulus gerovinus est rotuli \({1 \over 6}\) 2 forfori, 136 quia si multiplicaverit³⁵⁵ rotulos 11 gerovi per \({1 \over 6}\) 2 [R:66v] facient³⁵⁶ rotulos \({5 \over 6}\) 23 forfori. Unde describe quod rotuli \({5 \over 6}\) 23 forfori valent karatos 17; quantum valent³⁵⁷ rotuli 9 forfori? Multiplicabis ergo 17 per 9³⁵⁸ que sunt ex adverso et divides³⁵⁹ per \({5 \over 6}\) 23: exibunt karati \({\phantom{1}5~~\phantom{1}5 \over 11~~13}\) 6.