The Task

Daniel had a jug with water in it. He poured 4/8 of the water out and was left with 3/8. How much was in his jug to start?

Teachers' Notes

Students can work out the solution to this contextual problem by visualising Daniel pouring the water out of the jug. Some students think of the problem as a subtraction (? - 4/8 = 3/8) and others use addition (3/8 + 4/8 = ?). Either way, the solution can be presented using the subtraction component of the add/subtract box.

You may want to model this using jugs and water in the classroom to help students to visualise the pouring out representing a 'take away' subtraction. Students could write their own tasks for their peers to answer using Fractions Lab.

To challenge more able students, Fractions Lab also represents some improper fractions. The next sample task provides an example.

You can also read how to subtract 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".