Adding And Subtracting Algebraic Fractions Lesson Plan 31651

mr-mathematics.com Lesson Planning Sheet Title: Adding & Subtracting with Algebraic Fractions Learning Objectives: By the end of the lesson:  

All students should be able to add and subtract a pair of algebraic fractions with numerical denominators. Most students should be able to add and subtract a pair of algebraic fractions in the form .

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Some students should be able to add and subtract a pair of algebraic fractions in the form

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Key words: Algebraic Fraction, Highest Common Factor, Simplify Learning Activities Starter/Introduction The starter is intended to provide an application for adding ordinary fractions since this is an essential skill throughout the lesson. The idea here is for students add the four fractions using their equivalences with a denominator of 18. Pose the problem for students to attempt on miniwhiteboards.

Resources: Mini-whiteboards

Development Emphasise the need to have a common denominator when adding or subtracting fractions. Explain or discuss how to calculate the highest common factor given numerical or algebraic denominators. A common misconception when subtracting one fraction from another is to not fully multiply out by the negative, e.g., -(2x+3) = -2x-3 as opposed to -2x+3. Work through the first few examples with the students so they can attempt the latter questions on the second slide on their own using mini-whiteboards. The questions on the third slide could then be attempted independently by the students. Plenary The two questions in the plenary are intended to consolidate the learning objectives for the core ability as well as challenge the most able. Therefore, it may be beneficial to encourage students to work in pairs to enable peer . Have the solutions presented on miniwhiteboards at the end for assessment and . Differentiation More able:  Having three fractions with denominators that are neither factors or multiples of each other will lead to a cubic numerator.  The concept of Partial Fractions could be introduced for the most able. Less Able  It may be wise having denominators as known values and the numerators as algebraic expressions one lesson so further progress can be made the in the next.