This book with the topic aforementioned aimed at understanding the Ethnomathematics that tinsmiths use in the optimization of cylindrical cans and trays. The participants were two tinsmiths from Vanduzi district which is 32 kilometers from the city of Chimoio - Manica province, in the first half of 2018. Literature review, interview and observation were the main methods used, from which the following results and conclusions emerged: The first tinsmith is concerned with maximizing the volume of the tray and he does it by trying. The second does not even know that it is possible to have a tray with a maximum volume. Regarding the cylindrical can, the first is concerned with minimizing the sheet metal when making trays; he only lacks the basic non-formal mathematics for this purpose. The second is not interested in how much sheet metal he spends; he associates the volume of the utensil with the price.