2.1 Matrices

• Order of a matrix
• Position of items in a matrix
• Compatibility of matrices
• Addition and subtraction of matrices

• identify a matrix in different situations
• determine the order of a matrix in different situations
• determine the position of items in a matrix in different situations
• determine the compatibility of matrices in addition and subtraction
• carry out addition and subtraction of matrices in real-life situations
• reflect on the use of matrices in real-life situations

“How do we use matrices in real-life situations?”

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1. What a matrix is
   40 min · 1 practice tasks · quiz
   A matrix is a block of numbers arranged in rows and columns and written inside brackets.
2. The order of a matrix
   40 min · 1 practice tasks · quiz
   The order of a matrix is written rows x columns, and it describes the shape of the block of numbers.
3. The position of an element
   40 min · 1 practice tasks · quiz
   Each element has an address written as a row number then a column number, such as a23.
4. Building a matrix from a table
   40 min · 1 practice tasks · quiz
   Write down what the rows and the columns will mean, then fill the numbers in that fixed order.
5. Compatibility: which matrices can be added
   40 min · 1 practice tasks · quiz
   Two matrices can be added or subtracted only when they have exactly the same order.
6. Adding matrices
   40 min · 1 practice tasks · quiz
   Add matrices of the same order by adding each element to the element in the same position.
7. Subtracting matrices
   40 min · 1 practice tasks · quiz
   Subtract element by element, keeping the two matrices the way round the question states.
8. Matrices at work in Kenya
   40 min · 1 practice tasks · quiz
   Use matrices on real Kenyan tables, checking the key matches before adding or subtracting.