Thinking about it more, writing a sum as 5 + (3 x 4) = ? is the beginning of using algebra - a way of logically setting out the sum for a problem which in words would be "I have five single oranges and three packs of four apples each. How many pieces of fruit do I have?" It gives the right (common sense) answer, which you wouldn't get by leaving out the brackets and working it out from left to right in the order it is written.
So it begins….. Streeting resigns
so I evidently wasn't concentrating