Lesson 26 Chunking in algebra

# Chunking in algebra

Overview Resources
This lesson carries forward the agenda of TM21: Expressions and equations. The breaking and recombining of individual numbers and terms is now extended to algebraic expressions. The individual numbers and terms may remain intact, but they can be combined in different ways to make up convenient chunks, using brackets. Worksheets 1 and 2
Exploring concepts underlying algebraic manipulations. Algebraic equations of various kinds.
EPISODE 1
Chunking of numeric expressions
Pupils consider the usefulness of scanning a long numeric expression of addition, and grouping two or more terms together to produce large but easy numbers to simplify calculations. They also break up a relatively complex number into easier components so as to ease multiplication. The implicit use of brackets is made explicit.
EPISODE 2
Chunking of linear algebraic expressions
Starting with a compound variable made up of a two-step linear relation in a real-life context, pupils consider what happens when it is multiplied by a number. The example of a necklace made up of variable length chain and a fixed size pendant is used, together with the price of gold.
EPISODE 3
Manipulating multiple variable and quadratic expressions
Further elaboration of the variable is approached in a real-life context of the cost of a scarf, which is dependent on the area of the fabric used, so that the nesting of variables is made evident visually as well as algebraically.