Understanding Fractions



Ø  After dividing each of 12 corn muffins in half, the teacher asks students to take notice that the two parts are the same size.  When the teacher is about to give each student a piece, a boy says, “I want the bigger half.”  Children often struggle with the concepts of half and other equal fractional portions because of their prior experiences of sharing or dividing things unequally.

Ø  Students have difficulty dividing nontraditional shapes into parts such as thirds.

Ø  Children who are only used to dividing traditional shapes such as squares, circles, and rectangles into equal parts begin to think that the way they divide these shapes will work for all shapes.

Ø  They are unable to identify the fraction of a set.  For example, if a set includes two cats and four dogs, students are likely to say that 2/4 of the animals are cats.

Ø  Some students have difficulty making sense of fractional names and vocabulary.  Instead of saying one-half, a child might apply a consistent naming system for fractions and say, “one twoth.”

Ø  Students also struggle with ranking written fractions.  Children frequently choose ¼ as larger than 1/3, overgeneralizing what they know about whole numbers and applying it to comparing and ordering fractions.  They do not yet understand that the larger the denominator, the smaller each of the equal parts in the whole. 

 

 Ideas for Instruction

·       Teachers need to engage students to divide concrete materials equally.

·       Explore the concept of fair shares.

·       Present a variety of shapes for students to divide so that students see that not all shapes are divided in the same way. 

·       Introduce vocabulary of fractional parts after students have explored a fractional situation.

·       Introduce fractional concepts in the context of things other than pizza!

·       Expose students to more than just haves, thirds, and fourths.

No comments:

Post a Comment

Subscribe to: Posts (Atom)