1964 SOUTH AFRICA - 50 CENTS .500 SILVER - 1st Decimal Series -Jan Van Riebeeck | eBay
Fractions, Percentages, Decimals and Proportions: A Learning-teaching ... - Frans van Galen, Els Feijs, Nisa Figueiredo, Koeno Gravemeijer, Els van Herpen, Ronald Keijzer - Google Books
Visual Fractions Decimals and Percentages – Microsoft-toepassings