Algebraic Expressions · JHS3 Mathematics

Lesson notes

Learning Objectives

Indicator: B9.2.2.1.2 - Substitute values into given formulae to evaluate it and use it to solve problems.

By the end of the lesson, learners can:

Substitute given numerical values into a formula accurately, following the correct order of operations.
Evaluate algebraic expressions involving positive and negative integers, squares and square roots.
Apply substitution to solve practical problems involving formulae for area, volume and other real-life quantities.
Verify the reasonableness of their answers by estimating before calculating.

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Curriculum details

Strand: Algebra (Strand 2)
Sub-strand: Algebraic Expressions (2.2)
Content standard: B9.2.2.1 - Demonstrate an understanding of (i) change of subject (ii) substituting values to evaluate expressions, and (iii) factorize expressions that have simple binomial as a factor.
Indicator: B9.2.2.1.2 - Substitute values into given formulae to evaluate it and use it to solve problems.
Suggested placement: Term 2, Week 6 (Week 18 of the year)
Our suggestion, laid out in curriculum order across three terms of twelve weeks. NaCCA does not fix the week, so follow your school's scheme of learning.
Curriculum reference: Mathematics, Common Core Programme (JHS1-JHS3), 2023, p. 185
Transcribed from the official NaCCA publication. Check this page against the source.

Exemplars (from the NaCCA curriculum)

E.g.1
i. Find the value of (x - b) 2 - 3(x - b) ifx = 2 adn b = -5
ii. Make k the subject of the formula: 1 k 2 + a 2 = √( )
n hg If n = 8 , a = 3, h = 2, g = 32, find the value of k. 5
iii. The formula for finding the volume of the shape below is given as 1 πr 2 h . Find the volume if r = 7, h = 21, and π = 22

Cone diagram labels its radius r and perpendicular height h for the volume formula one-third pi r squared h. Visible... — A cone diagram labels its radius r and perpendicular height h for the volume formula one-third pi r squared h. Visible labels, values, and notation include: Tr2h. Find the volume ifr = 7, h = 21,a; h.

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