Elinye igama lala manani kuthiwa angamanani a-positive. ngamanye amaxesha laa manani abhalwa njengo-+1 ukubonisa okokuba ahlukile kwamanye amanani waziwa ngokuba ngamanani a-negative numbers. Nangona kunjalo qaphela okokuba akusingawo onke amanani a-positive abanatural. Inani lisenokuba positive kodwa lingabikho natural (Umzekelo, i-