Fraction Classroom

Explore and explain · Grades 3–5

Make the fraction visible.

Choose a model, build the task, then explain the result. Every control works with a keyboard. Print a task sheet or download your model to keep the reasoning.

2 wholes, 4 intervals per whole. Point at 1/4; 1 intervals traveled.01/42/43/415/46/47/421 intervals from 0; point = 1/4

Number Line Lab

Count equal intervals, move a point beyond one, and preserve its location while renaming a fraction.

3 guided investigations · Student and teacher materials

Fix the distance from 0 to 1 before counting intervals. A fraction labels a point at a distance from zero; it does not label the space between ticks.

Open model
Strip A: 1/4 of 12 centimeters = 3 centimeters. Strip B: 1/3 of 12 centimeters = 4 centimeters.A: whole = 12 cm1/4 of this whole = 3 cmB: whole = 12 cm2/6 of this whole = 4 cmSame whole: combined shaded fraction = 7/12

Fraction Strip Lab

Compare wholes, repartition fractions, add unlike units, and distinguish two meanings of division.

5 guided investigations · Student and teacher materials

The centimeter labels make the whole explicit. Compare physical shaded lengths and fraction names separately. Use the sharing and counting tasks to name what the quotient measures.

Open model
One square unit. 1 of 4 rows and 2 of 6 columns; overlap 2 of 24 cells, equal to 1/12 square unit.1/4 × 2/6 = 1/12Whole square = 1 square unit; dark overlap is the product

Area Product Lab

Select rows and columns, count their overlap, and connect fractional side lengths to square units.

3 guided investigations · Student and teacher materials

The complete rectangle represents one square unit. Only the double-shaded intersection represents the product; a selected row or column alone represents one factor.

Open model

Use a model to respond to an error

A model is useful when its whole, unit and operation match the question. Ask a student to name the whole before calculating, then change one feature and explain what stays fixed.