Combined operations refers to problems where you need to do more than one operation.
- Repeated operations are where the same operation is applied many times (e.g. repeated addition of non-equal sets).
- Mixed operations are where different operations need to be coordinated (e.g. multiplying first then adding, or adding first then multiplying).
Combined operations are important because they:
- are common in daily life
- assist students to differentiate between the processes involved in the four operations
- provide opportunities for flexible strategic choice.
Repeatedly carrying out the same operation offers opportunity for choices. Changing the order of using the numbers in a problem can simplify the calculation. Repeated multiplication and division lay important understandings that are required for the development of rational number.
Many everyday problems require the coordination of several calculations. Where the calculations are different operations, for example multiplication and addition, students must make decisions about order of calculation and the storing of answers.