For example, 100 invested for one year, earning 5% interest, will be worth 105 after one year; therefore, 100 paid now and 105 paid exactly one year later both have the same value to a recipient who expects 5% interest. That is, 100 invested for one year at 5% interest has a future value of 105. This notion dates back at least to Martín de Azpilcueta (1491–1586) of the School of Salamanca.