Some researchers have argued that children's earliest symbols are based on their sensorimotor experience and that arbitrary symbol-referent mapping poses a challenge for them. If so, exposure to iconic symbols (such as one-finger-for-one-object manual gestures) might help children in a difficult domain such as number. We assessed 44 preschoolers' processing of number gestures and number words on two tasks: give-a-number and how-many. Children were generally more accurate when mapping number words than number gestures onto a number of toys, suggesting that the iconicity of number gestures does not help children map symbols to numbers. We argue that children learn number gestures as arbitrary symbols and do not take advantage of their iconicity. (Contains 5 figures and 2 tables.)