The scale is loaded with between 1 and 4 weights. The user then has to balance the scales, converting between g and kg in the process. There is a great deal of control over the level.
A great starter to explore addition, subtraction / difference and partitioning as well as the relationship between grams and kilog More…rams. Levels include converting whole kg to g (and vice versa), converting fractions of kg (eg 1/4kg = 250g) and weights in kg to 1 and 2 decimal places.
Match the equivalent fractions, decimals and percentages. Alternatively, you can choose to convert between just fractions and decimals, or between fractions and percentages or decimals and percentages. Diagrams to show equivalence can be turned on or off.