If it is even, halve it, and write the answer in its place. ¶ Here is the first case of þis craft, þe quych is þis, yf þe first figure be euen. þou schal take away fro þe figure euen halfe, & do away þat figure and set þere þat leues ouer, as þus, 4. take leaf 149 b. *halfe out of 4, & þan þere leues 2. do away 4 & sett þere 2. þis is lyght y-nowȝt. versus.
The Mediation of an Odd Number.
¶ Impar si fuerit vnum demas mediare
Quod non presumas, sed quod superest mediabis
Inde super tractum fac demptum quod notat vnum.
If it is odd, halve the even number less than it. Here is þe secunde case of þis craft, the quych is þis. yf þe first figure betokene a nombre þat is odde, the quych odde schal not be [mediete], þen þou schalt medye þat nombre þat leues, when the odde of þe same nombre is take away, & write þat þat leues as þou diddest in þe first case of þis craft. Whaɳ þou [hayst] write þat. for þat þat leues, Then write the sign for one-half over it. write such a merke as is here w vpon his hede, þe quych merke schal betokeɳ halfe of þe odde þat was take away. Here is an example. lo an Ensampull. 245. the first figure here is betokenynge odde nombre, þe quych is 5, for 5 is odde; þere-fore do away þat þat is odde, þe quych is 1. þen leues 4. þen medye 4 & þen leues 2. do away 4. & sette þere 2, & make such a merke w upon his hede, þat is to say ouer his hede of 2 as þus. 242.w And þen worch forth in þe oþer figures tyll þou come to þe ende. by þe furst case as þou schalt vnderstonde þat Put the mark only over the first figure. þou schalt leaf 150 a. *neuer make such a merk but ouer þe first figure hed in þe riȝt side. Wheþer þe other figures þat comyɳ after hym be eueɳ or odde. versus.
The Cases of the Craft of Mediation.
¶ Si monos, dele; sit tibi cifra post nota supra.
If the first figure is one put a cipher. ¶ Here is þe thryde case, þe quych yf the first figure be a figure of 1. þou schalt do away þat 1 & set þere a cifer, & a merke ouer þe cifer as þus, 241. do away 1, & sett þere a cifer with a merke ouer his hede, & þen hast þou ydo for þat 0. as þus 0w þen worch forth in þe oþer figurys till þou come to þe ende, for it is lyght as dyche water. vnde versus.
¶ Postea procedas hac condicione secunda: