Calculer mentalement chacune des opérations suivantes.
\(\displaystyle{18,2+14,8}\)
\(\displaystyle{6,79+11,11}\)
\(\displaystyle{23+46+84+37}\)
\(\displaystyle{8,2+6,7+3,8+0,3}\)
\(\displaystyle{41,9+12,5+24,5+31,1}\)
\(\displaystyle{4,65+1,74+3,35+6,26}\)
\(\displaystyle{57+133}\)