It is a very simple challenge or challenge. It is to put money for 52 weeks in a can, jar or a box that we can use.
The challenge is to put every week, the amount of money equivalent to the number of week that touches us. Thus, in Week 1 will deposit 1 (w / dollar), week 23 will deposit 23 (pesos / dollars) and so on to reach the week number 52, which will last 52 (pesos / dollars).
Source: http://cosasdedinero.com/2015/03/17/destripamos-el-reto-del-ahorro-en-52-semanas/