purpose of these diagnostic tests is to diagnose how students
are thinking when doing written subtraction and multiplication.
referring to the common errors in subtraction and multiplication
activities on this resource, you can see how our 'example' children
would have completed these tests and the resulting patterns
of their right and wrong answers.
a child may have developed their own defective algorithm(s),
they may not always be consistent in their application of
it. In some cases this may be because they learn as the test
prompts them to think more carefully about the task. It also
may be because different test items prompt a confused mix
using the tests, compare your results with the completed example
tests to look for a similar pattern. Then refer to the possible
teaching strategies suggested for some common errors in written
subtraction and multiplication.