### Teorija

Atceries skaitļu šķiras!

Uzdevums:
Saskaiti vienu zem otra $\phantom{\rule{0.147em}{0ex}}37+42$.

Saskaitāmos raksta vienu zem otra tā, lai
1. vieni ir zem vieniem,
2. desmiti ir zem desmitiem.

 +$\begin{array}{l}3\phantom{\rule{0.147em}{0ex}}7\\ \underset{¯}{4\phantom{\rule{0.147em}{0ex}}2}\\ 7\phantom{\rule{0.147em}{0ex}}9\end{array}$ 7 vieni plus 2 vieni ir 9 vieni,         7 + 2 = 9,   šos 9 vienus raksta zem vieniem,  3 desmiti plus 4 desmiti ir 7 desmiti,         3 + 4 = 7,šos 7 desmitus raksta zem desmitiem.  Iegūta summa 7 desmiti un 9 vieni jeb 79.
 +$\begin{array}{l}\left(1\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\\ \phantom{\rule{0.147em}{0ex}}4\phantom{\rule{0.147em}{0ex}}7\\ \underset{¯}{\phantom{\rule{0.735em}{0ex}}9}\\ \phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}..6\end{array}$ 7 vieni plus 9 vieni ir 16 vieni ir 1 desmits un 6 vieni.  6 raksta zem vieniem, bet 1 desmitu patur prātā vai raksta virs desmitiem. +$\begin{array}{l}\left(1\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\\ \phantom{\rule{0.147em}{0ex}}4\phantom{\rule{0.147em}{0ex}}7\\ \underset{¯}{\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}9}\\ \phantom{\rule{0.147em}{0ex}}5\phantom{\rule{0.147em}{0ex}}6\end{array}$ 4 desmiti plus 1 desmits ir 5 desmiti  5 desmitus raksta zem desmitiem.  Iegūta summa: 5 desmiti un 6 vieni jeb 56.