The Task

George says 1/6 + 2/6 = 3/12. Do you agree or disagree with George? Use the add/subtract box to check your explanation. Was the outcome as you expected? Why/why not?

Teachers' Notes

This task challenges the common misconception of adding across the numerators and the denominators.

You may wish to discuss with students their initial thoughts about the sum before they use Fractions Lab to respond: this would be interesting formative assessment for you about your students' understanding of adding fractions and how they treat the numerators and denominators.

You can also read how to add fractions with like denominators by reading the Quick Start Guide, "Adding and subtracting fractions" and how to check them in "The operations box: compare, add or subtract".