CTET Class I to V 21 Jan 2024 Shift 2 Paper

While solving $\mathrm{begin}\mathit{m}\mathit{a}\mathit{t}\mathit{r}\mathit{i}\mathit{x}182\backslash -67\backslash \mathrm{end}\mathit{m}\mathit{a}\mathit{t}\mathit{r}\mathit{i}\mathit{x}$
in class II, a teacher explained that we have to subtract 7 from 2 and 2 is smaller than 7. So we will borrow one from 8 and then we can subtract 7 from 12. One student told teacher : Mam ! why we are borrowing from eight, as borrowing is not good. What a teacher should do in such a situation?