Comparing E
Comparing Fractions
Compare fractions with unlike numerators and unlike denominators using models and symbols
Applying a variety of strategies to compare any two fractions, including comparing to benchmarks, using proportional reasoning or determining a common fractional unit (denominator) supports understanding of value.
Background
Comparing and ordering fractions allows students to develop a sense of fraction as quantity, as well as a sense of the size of a fraction, both necessary prior knowledge components for understanding fraction operations (Johanning, 2011).
Comparing and ordering fractions with different fractional units (or denominators) leads students to identify the need for equivalent fractions. When students determine an equivalent fraction they are changing the unit of measure by either splitting or merging the partitions of the original fraction. The following illustration demonstrates these concepts using an area model:
Splitting to determine an equivalent fraction for 2⁄3
Merging to determine an equivalent fraction for 6⁄8
The exploration of equivalence allows students to develop an understanding of equivalent fractions as simply being a different way of naming the same quantity; it also supports them in viewing the fraction as a numeric value. A solid understanding of equivalence helps students with fractions operations, especially addition and subtraction.
References:
Johanning, D. I. (2011). Estimation's role in calculations with fractions.Mathematics Teaching In the Middle School, 17(2), 96-102.
Tasks
Pretty Powerful Paper Folding
Students fold colourful paper strips into equal parts that represent unit fractions and label the folded regions using symbolic notation. These strips are powerful visual tools that allow students to see the relative size of fractional regions, which allows them to compare familiar fractional quantities.
Comparing Fractions
This is a set of prompts consisting of purposefully paired fractions to elicit the use of various strategies. The prompts may be used on different occasions for either Minds-On activities or for Action tasks depending on student readiness.
Additional Prompts
These tasks emerged out of the fraction research. Teachers may wish to use them as diagnostic or summative assessments, exit cards, number talk prompts, or additional practice questions. By considering both the specifics of the cell and student use of purposeful models, teachers can support students in acquiring a strong conceptual understanding.