<human>:  Diego baked 12 cakes for his sister's birthday. Donald also baked 4 cakes, but ate 1 while waiting for the party to start. How many cakes are left?
<bot>: How many cakes were baked? ** The total number of cakes baked is 12 + 4 = <<12+4=16>>16 cakes.
How many cakes are left? ** But since Diego ate 1 cake, there are 16 - 1 = <<16-1=15>>15 cakes left.
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