Unit 5
Fracciones como números
Unit Goals
- Students develop an understanding of fractions as numbers and of fraction equivalence, by representing fractions on diagrams and number lines, generating equivalent fractions, and comparing fractions.
Unit Narrative
In this unit, students make sense of fractions as numbers, using various diagrams to represent and reason about fractions, compare their sizes, and relate them to whole numbers. The denominators of the fractions explored here are limited to 2, 3, 4, 6, and 8.
In grade 2, students partitioned circles and rectangles into equal parts and used the language “halves,” “thirds,” and “fourths.” Students begin this unit in a similar way, by reasoning about the sizes of shaded parts in shapes. Next, they create fraction strips by folding strips of paper into equal parts, and later represent the strips as tape diagrams.
Using fraction strips and tape diagrams to represent fractions prepare students to think about fractions more abstractly as lengths and locations on the number line. This work builds on students’ prior experience with representing whole numbers on the number line.
In each representation, students take care to identify 1 whole. This helps them reason about the size of the parts and whether a fraction is less than or greater than 1. (Fractions greater than 1 are not treated as special cases.)
Students then use these representations to learn about equivalent fractions and to compare fractions.
They see that fractions are equivalent if they are the same size or at the same location on the number line, and that some fractions are the same size as whole numbers.
Later in the unit, students compare fractions with the same denominator and those with the same numerator. They recognize that as the numerator gets larger, more parts are counted, and as the denominator gets larger, the size of each part that makes up the whole gets smaller.