Matching Pairs mosaico calculoOnline version mosaico de cálculo mental by Carlos San Mar 1 41 + 15 2 15 + 8 3 48 ÷ 4 4 15 - 9 5 30 - 11 6 33 - 11 7 25 x 3 8 36 ÷ 4 9 33 + 7 10 10 - 6 11 5 x 5 12 19 + 1