1. Order of Operations (BIDMAS): Commutativity involving subtraction
Silent
Teacher
Intelligent Practice
Narration
Your Turn
10−2 ×3
10−2×3
2×3−10
10− 2 2 ×3
2 2 ×3−10
Practice

2. Worked Example
Your Turn
Work out:
20 – 4 × 2.5
4 × 2.5 − 20
20 – 4 ×
20 – 4 ×
Work out:
30 – 3.5 × 2
3.5 ×2−30
30 – 3.5 × 2 + 5
30 – 3.5 ×
The idea here is to follow the order of operations but keep the calculation written in the same order from left to right.
For example, 20 – 4 x 2.5 would become 20 – 10, not 10 – 20. Subtraction is NOT commutative so it matters that the 20 stays at the front of the calculation.
@mathsmrgordon

3. Work out: 10 −3×2 3×2−10 3×10−2 3× 10−2 10−2 ×3 10−2×3 10− 2 2 ×3
2 2 ×3−10
10 2 −3×2
10 2 −3 2+4
10 2 −3 2+4×5
@mathsmrgordon

4. Work out: 10 −3×2 4 3×2−10 −4 3×10−2 28 3× 10−2 24 10−2 ×3 10−2×3
10− 2 2 ×3
2 2 ×3−10
10 2 −3×2
10 2 −3 2+4
10 2 −3 2+4×5 4 −4 28 24 -2 2 94 82 34
@mathsmrgordon