þen worch forth to þe nex fig{ur}e. And also it is no mayst{er}y yf þ{ere} come no figur{e} after þat on is medyet, þ{o}u schalt write no 0. ne nowȝt ellis, but set 5 ou{er} þe next fig{ur}e afor{e} toward þe ryȝt, as þus 14. medie 4 then leues 2, do away 4 & sett þ{ere} 2. þen medie 1. þe q{ui}ch is rekende for ten, þe halue{n}del þ{ere}-of wel be 5. sett þ{a}t 5 vpon þe hede of þ{a}t figur{e}, þe quych is now 2, & do away þ{a}t 1, & þou schalt haue þis nombre yf þ{o}u worch wel, 5  2. vn{de} v{er}sus. [Headnote: How to prove the Mediation.] ¶ Si mediacio sit b{e}n{e} f{ac}ta p{ro}bar{e} valeb{is} ¶ Duplando num{er}u{m} que{m} p{ri}mo di{m}ediasti [Sidenote: How to prove your mediation. First example. The second. The third example. The fourth example. The fifth example.] ¶ Her{e} he telles þe how þou schalt know wheþ{er} þou hase wel ydo or no. doubul [*leaf 151b] þe nombre þe quych þ{o}u hase mediet, and yf þ{o}u haue wel y-medyt after þe dupleacioɳ, þou schalt haue þe same nombre þat þ{o}u haddyst in þe tabull{e} or þ{o}u began to medye, as þus. ¶ The furst ensampull{e} was þis. 4. þe quych I-mediet was laft 2, þe whych 2 was write in þe place þ{a}t 4 was write afor{e}. Now doubull{e} þat 2, & þ{o}u schal haue 4, as þ{o}u hadyst afor{e}. þe secunde Ensampull{e} was þis, 245. When þ{o}u haddyst mediet all{e} þis nomb{re}, yf þou haue wel ydo þou schalt haue of þ{a}t mediacioɳ þis nombre, 122ʷ. Now doubull{e} þis nombre, & begyn in þe lyft side; doubull{e} 1, þat schal be 2. do away þat 1 & sett þ{ere} 2. þen doubull{e} þ{a}t oþ{er} 2 & sett þ{ere} 4, þen doubull{e} þat oþ{er} 2, & þat wel be 4. þe{n} doubul þat merke þat stondes for halue on. & þat schall{e} be 1. Cast þat on to 4, & it schall{e} be 5. do away þat 2 & þat merke, & sette þ{ere} 5, & þen þ{o}u schal haue þis nombre 245. & þis wos þe same nombur þ{a}t þ{o}u haddyst or þ{o}u began to medye, as þ{o}u mayst se yf þou take hede. The nombre þe quych þou haddist for an Ensampul in þe 3 case of mediacioɳ to be mediet was þis 241. whan þ{o}u haddist medied all{e} þis nombur truly [*leaf 152a] by eu{er}y figur{e}, þou schall haue be þ{a}t mediacioɳ þis nombur 120ʷ. Now dowbul þis nomb{ur}, & begyn in þe lyft side, as I tolde þe in þe Craft of duplacioɳ. þus doubull{e} þe fig{ur}e of 1, þat wel be 2. do away þat 1 & sett þ{ere} 2, þen doubul þe next figur{e} afore, the quych is 2, & þat wel be 4; do away 2 & set þ{ere} 4. þen doubul þe cifer, & þat wel be noȝt, for a 0 is noȝt. And twyes noȝt is but noȝt. þ{ere}for{e} doubul the merke aboue þe cifers hede, þe quych betokenes þe halue{n}del of 1, & þat schal be 1. do away þe cifer & þe merke, & sett þ{ere} 1, & þen þ{o}u schalt haue þis nombur 241. And þis same nombur þ{o}u haddyst afore or þ{o}u began to medy, & yf þ{o}u take gode hede. ¶ The next ensampul þat had in þe 4 case of mediacioɳ was þis 4678. Whan þ{o}u hast truly ymedit all{e} þis nombur fro þe begynnyng{e} to þe endyng{e},