My son (in Y6) is doing Schofield & Simms Mental Arithmetic 6 Section 2, test 4 for homework, and question A1 is 1000 - 587 + 133 = ?
The correct answer is 526, but he's insisting it is 280, and I'm having trouble explaining why it isn't.
The problem is he's been taught to use BIDMAS, but I'm not sure it hasn't been explained to him correctly, or at least he doesn't yet understand it correctly, so he is insisting on doing the addition (i.e. 587 + 133) first, without taking into account the fact that -587 is a negative number.
We've had the same problem before, and while I'm usually pretty confident at explaining maths, I'm struggling to get this across clearly. (I did BIDMAS in secondary school, and I'm pretty sure we did bracket expansion first, so I wouldn't have had the same problem).
How can it best be explained?