1. A data input device for inputting numeric data by voice, the data input device comprising: a holder operable to hold numeric data input in the past; a calculator operable to calculate a prediction range of a value expected to be input on the basis of the numeric data held in the holder; a speech recognizer operable to perform speech recognition of input speech representing a value; a determiner operable to determine whether or not a value represented by a recognition result obtained by the speech recognizer is within the prediction range calculated by the calculator; and a presenter operable to present details corresponding to the determined result.