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De centenario coriorum98
Si coria 100 valent libras \({1 \over 9}\) \({3 \over 5}\) 83, quantum valent coria 32? Describe numeros,
[R:61r] et multiplica \({1 \over 9}\) \({3 \over 5}\) 83 per 32, ideo quod ponuntur ex adverso, et divide multiplicationem eorum per 100, hoc est multiplica 83 per suas virgulas; erunt 3767, que pone super \({1 \over 9}\) \({3 \over 5}\) 83, et proba ea per quamlibet pensarum preter quam per 9.
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Deinde multiplica 3767 per 32;
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① £ |
4 |
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3767 |
cor. |
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\({1 \over 9}\) \({3 \over 5}\) 83 |
100 |
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② |
④ |
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\({1~~0~~0~~\phantom{1}9~~15 \over 3~~5~~5~~12~~20}\) 26 |
32 |
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99 erunt 120544, que divide per 100 et per \({1~~0 \over 5~~9}\) et apta ea ut habeas in capite virgule \({\phantom{1}1~~\phantom{1}0 \over 12~~20}\) sic: de 100 fac \({1~~\phantom{1}0 \over 5~~20}\) et de \({1 \over 9}\) fac \({1~~0 \over 3~~3}\), et accipe unam tertiam
100 illarum et multiplicabis eam per 4 ideo quod faciunt 12, et pone ipsa 12 post 20, ut superius facere demonstravimus, et apta reliquas fractiones post ipsam \({1~~0 \over 12~~20}\), et habebis in virgula divisionis \({1~~0~~0~~\phantom{1}0~~\phantom{1}0 \over 3~~5~~5~~12~~20}\).
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Et quia minuit nobis \({1 \over 4}\) de ipsis 12, pone 4 super 100 ut habeas ea tenacius memorie commendata cum acceperis pensam. Et multiplica in ea 120544
101; erunt 482176, que divide per \({1~~0~~0~~\phantom{1}0~~\phantom{1}0 \over 3~~5~~5~~12~~20}\): exibunt \({1~~0~~0~~\phantom{1}9~~15 \over 3~~5~~5~~12~~20}\) 26 pro pretio illorum 32 coriorum, ut superius in descriptione cernitur.
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Rursus rotuli 100 valent libras \({1 \over 7}\) \({1 \over 4}\) 23; quid ergo valent rotuli \({2~~\phantom{1}3 \over 5~~13}\) 64? Describe questionem, et multiplica 23 per suas virgulas
102: erunt 655, que pone super 23 et proba ea per pensam si recta sint. Deinde multiplica 64 per suam virgulam; erunt 4177, et multiplica ipsa per 655: erunt 2735935, que optime probare non negligas. Et divide ipsum numerum per
103 100 et per fractiones utrorumque numerorum
104 qui positi sunt ex adverso, optime insimul videlicet aptatas ita ut habeas in capite virgule \({\phantom{1}1~~\phantom{1}0 \over 12~~20}\), quod
[G:63r] sic facias:
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de 100 facias \({1~~\phantom{1}0 \over 5~~20}\), et vide si poteris de reliquis fractionibus divisionis extrahere ut habeas inde totum
105 12 vel aliquam ipsius partem; de quibus tantum \({1 \over 4}\) potes habere de partibus de 12, hoc est ex illius compositione: ergo minuunt nobis 3 ut habeamus 12 in virgula post 20.
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Quare pone 3
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⑦ |
3 |
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655 |
℞ |
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\({1 \over 7}\) \({1 \over 4}\) 23 |
100 |
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⑥ |
① |
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pensa per 9 |
4177 |
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\({1~~5~~10~~\phantom{1}7~~\phantom{1}0 \over 5~~7~~13~~12~~20}\) 15 |
\({2~~3 \over 5~~13}\) 64 |
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106 super 100 ut in questione ostenditur, ut ipsa tenaci
107 memorie reserves, et apta reliquos numeros
[S:43r] divisionis post \({\phantom{1}1~~\phantom{1}0 \over 12~~20}\) sic: \({1~~0~~0~~\phantom{1}0~~\phantom{1}0~~\phantom{1}0 \over 5~~5~~7~~13~~12~~20}\); et multiplica 2735935
108 per 3 servata super 100; erunt 8207805, que iterum proba per pensam et divide ea per \({1~~0~~0~~\phantom{1}0~~\phantom{1}0~~\phantom{1}0 \over 5~~5~~7~~13~~12~~20}\); exibunt \({0~~1~~5~~10~~\phantom{1}7~~\phantom{1}0 \over 5~~5~~7~~13~~12~~20}\) 15 pro pretio quesitorum rotulorum. Et est pensa illarum
[A:24r] 1 per pensam de 11
109, ut superius in descriptione cernitur.
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