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