The couple want 3 slices each for a total of 2*3 = <<3*2=6>>6 slices
The children want 1 slice each for a total of 1*6 = <<1*6=6>>6 slices
They want 6+6 = <<6+6=12>>12 slices in total
Each pizza has 4 slices so they need 12/4 = <<12/4=3>>3 pizzas
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