¶ Postea procedas reliquas demendo figuras.
A very hard case is put. ¶ Here he puttes þe fourte case, þe quych is þis, yf it happe þat þe neþer figure, þe quych þou schalt draw out of þe hier figure be more pan þe hier figur ouer hym, & þe next figure of two or of thre or of foure, or how mony þere be by cifers, how wold þou do. Þou [wost] wel þou most nede borow, & þou mayst not borow of þe cifers, for þai haue noȝt þat þai may [lene] or spare. Ergo[4] how woldest þou do. Certayɳ þus most þou do, þou most borow on of þe next figure significatyf in þat rewe, for þis case may not happe, but yf þere come figures significatyf after the cifers. Whan þou hast borowede þat 1 of the next figure significatyf, sett þat on ouer þe hede of þat figure of þe quych þou wold haue draw þe neþer figure out yf þou hadest myȝt, & reken it for ten as þou diddest in þe oþer case [here-a-fore]. Whaɳ þou hast þus y-do loke how mony cifers þere were bye-twene þat figure significatyf, & þe figure of þe quych þou woldest haue y-draw the leaf 145 a. *neþer figure, and of euery of þe ylke cifers make a figure of 9. Here is an example. lo an Ensampulle after. 40002
10004 Take 4 out of 2. it wel not be. borow 1 out of be next figure significatyf, þe quych is 4, & þen leues 3. do away þat figure of 4 & write þere 3. & sett þat 1 vppon þe figure of 2 hede, & þan take 4 out of ten, & þan þere leues 6. Cast 6 to the figure of 2, þat wol be 8. do away þat 6 & write þere 8. Whan þou hast þus y-do make of euery 0 betweyn 3 & 8 a figure of 9, & þan worch forth in goddes name. Sic. 39998
10004 & yf þou hast wel y-do þou[5] schalt haue þis nomber
How to prove the Subtraction.
¶ Si subtraccio sit bene facta probare valebis
Quas subtraxisti primas addendo figuras.
How to prove a subtraction sum. ¶ Here he teches þe Craft how þou schalt know, whan þou hast subtrayd, wheþer þou hast wel ydo or no. And þe Craft is þis, ryght as þou [subtrayd] þe neþer figures fro þe hier figures, ryȝt so adde þe same neþer figures to þe hier figures. And yf þou haue well [y-wroth] a-fore þou schalt haue þe hier nombre þe same þou haddest [or] þou be-gan to worch. as for þis I bade þou schulde kepe þe neþer figures stylle. Here is an example. lo an leaf 145 b. *Ensampulle of alle þe 4 cases togedre. worche welle þis case 40003468
20004664 And yf þou worch welle whan þou hast alle subtrayd þe þat hier nombre here, þis schalle be þe nombre here foloyng whan þou hast subtrayd. 39998804
20004664 Our author makes a slip here (3 for 1). And þou schalt know þus. adde þe neþer rowe of þe same nombre to þe hier rewe as þus, cast 4 to 4. þat wol be 8. do away þe 4 & write þere 8. by þe first case of addicioɳ. þan cast 6 to 0 þat wol be 6. do away þe 0, & write þere 6. þan cast 6 to 8, þat wel be 14. do away 8 & write þere a figure of 4, þat is þe digit, and write a figure of 1. þat schall be-token ten. þat is þe articul vpon þe hed of 8 next after, þan reken þat 1. for 1. & cast it to 8. þat schal be 9. cast to þat 9 þe neþer figure vnder þat þe quych is 4, & þat schalle be 13. do away þat 9 & sett þere 3, & sett a figure of 1. þat schall be 10 vpon þe next figuris hede þe quych is 9. by þe secunde case þat þou hadest in addicioɳ. þan cast 1 to 9. & þat wol be 10. do away þe 9. & þat 1. And write þere a cifer. and write þe articulle þat is 1. betokenynge 10. vpon þe hede of þe next figure toward þe lyft side, þe quych leaf 146 a. *is 9, & so do forth tyl þou come to þe last 9. He works his proof through, take þe figure of þat 1. þe quych þou schalt fynde ouer þe hed of 9. & sett it ouer þe next figures hede þat schal be 3. ¶ Also do away þe 9. & set þere a cifer, & þen cast þat 1 þat stondes vpon þe hede of 3 to þe same 3, & þat schalle make 4, þen caste to þe ylke 4 the figure in þe neyþer rewe, þe quych is 2, and þat schalle be 6. and brings out a result. 60003468
20004664 And þen schal þou haue an Ensampulle aȝeyɳ, loke & se, & but þou haue þis same þou hase [myse-wroȝt].
The Craft of Duplation.
Sequitur de duplacione
Si vis duplare numerum, sic incipe primo
Scribe figurarum seriem quamcunque velis tu.