||o o °
o°o oo°o o
o°o o o °
o°

118 a. *Then do I adde the 90 nexte aboue to the 50, and it maketh 140, therfore I take vp those 6 counters, and for them I sette 1 to the hundredes in ye thyrde lyne, and 4 in ye second lyne, thus.

||o o °
o°o oo°o o o
o o o o
°o

Then do I come to the hundredes, of whiche I fynde 8 in the fyrst summe, and 9 in ye second, that maketh 1700, therfore I take vp those 9 counters, and in theyr stede I sette 1 in the .iiii. lyne, and 1 in the space nexte beneth, and 2 in the thyrde lyne, as you se here.

||o oo°
o°o
o o o o
o°

Then is there lefte in the fyrste summe but only 2000, whiche I shall take vp from thence, and set 118 b. *in the same lyne in ye second summe, to ye one yt is there all redy: and then wyll the hole summe appere (as you may wel se) to be 8746, which was ye fyrst grosse summe, and therfore I do perceaue, that I hadde well subtracted before.

Xo o°o
o o°
o o o o
°o

And thus you may se how Subtraction maye be tryed by Addition.

S. I perceaue the same order here wt counters, yt I lerned before in figures.

M. Then let me se howe can you trye Addition by Subtraction.