The Golden Rule of Math Operations: BIDMAS/BODMAS

BIDMAS (or sometimes BODMAS) is a set of rules that tells us the order to use when solving math problems with different operations, like addition, subtraction, and multiplication.

Think of BIDMAS as your secret code to making sure you solve math expressions in the correct order

How to Use BIDMAS

Step-by-Step Breakdown

When you see an expression with multiple operations, go through BIDMAS in order. Here’s how it works:

1. Brackets: Do everything inside brackets first.
2. Indices: Then handle any powers or roots.
3. Division and Multiplication: Work from left to right.
4. Addition and Subtraction: Finally, work from left to right on these.

Example: Using BIDMAS

Let's look at the expression: $$5 + 3 \times (2 + 4)$$

1. Brackets: Solve $2 + 4 = 6$, so the expression becomes: $$5 + 3 \times 6$$
2. Multiplication: Next, do $3 \times 6 = 18$: $$5 + 18$$
3. Addition: Finally, $5 + 18 = 23$

So the answer is $23$

 

Example 2: Including Indices

Let's try something with an exponent: $$4 \times (3 + 2)^2 -5$$

1. Brackets: Inside the brackets, $3 + 2 = 5$: $$4 \times 5^2 - 5$$
2. Indices: Next, solve $5^2 = 25$: $$4 \times 25 - 5$$
3. Multiplication: Then, $4 \times 25 = 100$: $$100 - 5$$
4. Subtraction: Finally, $100 - 5 = 95$

So the answer is: $$95$$

Why is BIDMAS/BODMAS Important?

Following the BIDMAS/BODMAS rule ensures that mathematical operations are performed consistently and correctly by everyone. Without it, the same problem could have multiple answers, leading to confusion and errors. It's especially crucial in complex expressions with various operations.

Worked Example

Calculate: $$6 + (3^2 - 4) \div 2$$

 

1. Brackets:

   • Indices inside brackets: $3^2 = 9$
   • Subtraction inside brackets: $9 - 4 = 5$
   • Now we have : $$6 + 5 \div 2$$
2. Division: $5 \div 2 = 2.5$ $$6 + 2.5$$
3. Addition: $6 + 2.5 = 8.5$

Answer: $8.5$