human
Gerald had 20 toy cars. He donated 1/4 of his toy cars to an orphanage. How many toy cars does Gerald have left?
assistant
How many toy cars did Gerald give away? ** Gerald gave away 20 x 1/4 = <<20*1/4=5>>5 of his toy cars.
How many toy cars does Gerald have left? ** Therefore, he is left with 20 - 5 = <<20-5=15>>15 toy cars.
#### 15