1. Rule of sign solving is known as VBODMAS:
- V stands for "Vinculum" or "Bar"
- B stands for "Bracket" (order as small,medium,big)
- O stands for "Of"
- D stands for "Divisibility"
- M stands for "multiplication"
- A stands for "Addition"
- S stands for "Subtraction".
2. Multiplication of signs:
1. Multiplication of two plus gives again a plus.
2. Multipication of two minus gives a plus.
3. Multiplication of one plus and one minus gives a minus.