What a matrix is, its order and special types, addition, subtraction, scalar multiplication, multiplying matrices, equal matrices and data matrices.
5 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
A spreadsheet is a matrix. Every row of your timetable, every column of prices — matrices organise tables of numbers so you can compute with them all at once.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
See how a matrix transforms a shape.
Copy these into your notebook in your own words — that is how they stick.
Rectangular array in rows and columns. Order = rows × columns.
Square, row, column, zero, identity I (1s on the diagonal).
Same order only; add or subtract corresponding entries.
Multiply every entry.
Columns of first = rows of second; product order m × p; row × column.
In general AB ≠ BA; AI = IA = A; (AB)C = A(BC).
Same order and equal entries → equations for unknowns.
Use matrix multiplication to compute totals such as cost or revenue.
3 quick games on this lesson. Earn XP and badges as you play — your best score for each game is saved. Games are for practice and do not change your exam readiness. More games in the Mathematics Arcade.
8 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better. Work each item on paper first.
Write full answers, then reveal the mark scheme and tick the points you earned (14 marks in total). Show all your working — method marks count. Your answers are saved on this device.
Question 1 [7 marks]
P = 1234 and Q = 0−152.
(a) Calculate P + Q. [1]
(b) Calculate 2P − Q. [2]
(c) Calculate PQ and QP, and state whether PQ = QP. [4]
Question 2 [7 marks]
A shop sells two items. On Monday it sold 20 of item A and 10 of item B. The unit prices are $5 for A and $8 for B.
(a) Write the sales as a row matrix and the prices as a column matrix. [2]
(b) Multiply the matrices to find the total revenue on Monday. [3]
(c) Given x+2,31,y−1 = 6,31,4, find x and y. [2]
Find these in your own past-paper booklets for extra timed practice. Items above are written in the style of these papers; any adapted from a specific question say so.