Prime and composite numbers worksheet for identifying and circling numbers from 1 to 50.

Let’s solve this step by step.

First, we need to remember what prime and composite numbers are:

- A prime number is a whole number greater than 1 that has only two factors: 1 and itself. For example, 2, 3, 5, 7 — you can’t divide them evenly by any other number except 1 and themselves.

- A composite number is a whole number greater than 1 that has more than two factors. That means it can be divided evenly by numbers other than just 1 and itself. For example, 4 (divisible by 1, 2, 4), 6 (divisible by 1, 2, 3, 6).

Also note: The number 1 is neither prime nor composite. So we skip it in both lists.

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Step 1: Circle all the prime numbers from 1 to 50

We go through each number from 2 to 50 and check if it’s prime.

Start with 2 → prime (only divisible by 1 and 2)
3 → prime
4 → not prime (divisible by 2)
5 → prime
6 → not prime (divisible by 2, 3)
7 → prime
8 → not prime
9 → not prime (3×3)
10 → not prime
11 → prime
12 → not prime
13 → prime
14 → not prime
15 → not prime (3×5)
16 → not prime
17 → prime
18 → not prime
19 → prime
20 → not prime
21 → not prime (3×7)
22 → not prime
23 → prime
24 → not prime
25 → not prime (5×5)
26 → not prime
27 → not prime (3×9)
28 → not prime
29 → prime
30 → not prime
31 → prime
32 → not prime
33 → not prime (3×11)
34 → not prime
35 → not prime (5×7)
36 → not prime
37 → prime
38 → not prime
39 → not prime (3×13)
40 → not prime
41 → prime
42 → not prime
43 → prime
44 → not prime
45 → not prime
46 → not prime
47 → prime
48 → not prime
49 → not prime (7×7)
50 → not prime

So the prime numbers between 1 and 50 are:

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47

(That’s 15 primes total.)

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Step 2: Circle all the composite numbers from 1 to 50

Composite numbers are all numbers greater than 1 that are NOT prime. And remember — 1 is skipped.

So from 2 to 50, remove the primes we found above, and also remove 1.

List of numbers from 1 to 50:

Remove 1 (neither)

Remove primes: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47

What’s left? Those are the composites.

Let’s list them:

4, 6, 8, 9, 10,
12, 14, 15, 16, 18,
20, 21, 22, 24, 25, 26, 27, 28,
30, 32, 33, 34, 35, 36,
38, 39, 40, 42, 44, 45, 46,
48, 49, 50

Count them: Let’s see — from 4 to 50, excluding primes and 1.

Total numbers from 1 to 50 = 50
Minus 1 (neither) = 49
Minus 15 primes = 34 composite numbers.

Yes, our list has 34 numbers.

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Final Answer:

Prime numbers to circle:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47

Composite numbers to circle:
4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50