From Monday to Friday, Elle practices 0.50 x 5 = <<0.50*5=2.5>>2.5 hours.
On Saturday, she practices 0.50 x 3 = <<0.50*3=1.5>>1.5 hours.
Each week, Elle practices piano for 2.5 + 1.5 = <<2.5+1.5=4>>4 hours.
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