How do you solve algebra perimeter and area questions in P6?
Here the letter sits on the side of a square or rectangle.
What your child learns here
Here the letter sits on the side of a square or rectangle. The Primary 6 child uses what is already known about perimeter and area, writes an expression or equation, and solves it.
Use shape properties to fill in unlabelled sides: opposite sides of a rectangle are equal, and all four sides of a square are equal.
Write the perimeter as all the sides added in one line, then collect like terms.
Form an equation from a given perimeter or area and solve it for the letter.
Tell apart the value of the letter, the length of a side and the perimeter, and give the one the question asks for.
Does the answer make sense?
Once your child finds the letter, every side built from it must come out as a positive length, and a square's four sides must all match. When the answer is a perimeter in terms of the letter, the number in front of the letter should be positive, so the outline grows with the letter.
How to practise these questions
Basic questions train adding labelled sides into one expression, sometimes with the total already known. Intermediate questions add a first step, such as finding a side from an area, or working out how much of a total was used. Challenge questions change a shape while keeping its outline, or join two figures with a linking equation. If a perimeter in terms of a letter will not come together, read the written step-by-step solution.
Questions parents ask
Is this algebra or geometry? Both skills are used. The equation comes from the Primary 6 algebra outcomes, and the facts about sides come from earlier work on the area and perimeter of rectangles and squares.
Does my child need to remember the perimeter and area formulas? Yes: perimeter is all the sides added, and area of a rectangle is length times breadth. Our lesson writes the perimeter out side by side before collecting, which keeps every side in view.
Can the letter work out to a fraction or a negative number? In the questions on this page the letter works out to a whole number. The syllabus keeps P6 equations to whole number coefficients, and the questions are set so every side length makes sense.
