Let us write an algorithm to check whether a number is odd or even.

Question

Accepted Answer

> [!TLDR]
> Divide the number by 2 and look at the remainder: remainder 0 means even, otherwise odd — a single IF/ELSE decision (the *selection* construct).

**The idea.** This example introduces **selection**: the algorithm's path depends on a condition. The mathematical fact is that every even number is exactly divisible by 2, so the remainder operator (MOD, `%` in Python) is the right tool — it answers "what is left over after dividing by 2?" in one step.

**Algorithm / pseudocode:**

```text
Step 1: INPUT num
Step 2: rem = num MOD 2
Step 3: IF rem == 0 THEN
            PRINT "Number is Even"
        ELSE
            PRINT "Number is Odd"
Step 4: STOP
```

**Flowchart (nodes and arrows):**

1. **Start** (oval)
2. ↓ **Input num** (parallelogram)
3. ↓ **Decision (diamond): "num MOD 2 = 0?"**
   - **Yes** → **Output "Number is Even"** (parallelogram) → Stop
   - **No** → **Output "Number is Odd"** (parallelogram) → Stop
4. **Stop** (oval)

**Python implementation:**

```python
num = int(input("Enter a number: "))
if num % 2 == 0:
    print("Number is Even")
else: …

Q.Let us write an algorithm to check whether a number is odd or even.

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Q.Let us write an algorithm to check whether a number is odd or even.

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