Prime numbers worksheet for students to identify and circle prime numbers from a list of numbers.

Problem Description:

The task is to identify and circle all the prime numbers from the given list of numbers. A prime number is defined as a number greater than 1 that is divisible only by itself and 1. The numbers 0 and 1 are neither prime nor composite.

Given Numbers:

The numbers are arranged in a grid format:
```
70, 65, 25, 16, 90
55, 61, 80, 77, 32
42, 60, 93, 29, 79
56, 54, 24, 18, 96
71, 26, 68, 20, 85
58, 30, 76, 46, 31
```

Solution Approach:

1. Definition Recap: A prime number is greater than 1 and has no divisors other than 1 and itself.
2. Check Each Number: For each number in the list, determine if it is divisible by any number other than 1 and itself. If it is, then it is not a prime number.
3. Eliminate Non-Prime Numbers: Numbers that are divisible by any other number (besides 1 and themselves) are not prime.
4. Identify Prime Numbers: Circle or mark the numbers that satisfy the prime number condition.

Step-by-Step Analysis:

#### Row 1:
- 70: Divisible by 2, 5, 7, 10, etc. → Not Prime
- 65: Divisible by 5, 13 → Not Prime
- 25: Divisible by 5 → Not Prime
- 16: Divisible by 2, 4, 8 → Not Prime
- 90: Divisible by 2, 3, 5, 6, 9, 10, etc. → Not Prime

#### Row 2:
- 55: Divisible by 5, 11 → Not Prime
- 61: Only divisible by 1 and 61 → Prime
- 80: Divisible by 2, 4, 5, 8, 10, etc. → Not Prime
- 77: Divisible by 7, 11 → Not Prime
- 32: Divisible by 2, 4, 8, 16 → Not Prime

#### Row 3:
- 42: Divisible by 2, 3, 6, 7, 14 → Not Prime
- 60: Divisible by 2, 3, 4, 5, 6, 10, 12, etc. → Not Prime
- 93: Divisible by 3, 31 → Not Prime
- 29: Only divisible by 1 and 29 → Prime
- 79: Only divisible by 1 and 79 → Prime

#### Row 4:
- 56: Divisible by 2, 4, 7, 8, 14 → Not Prime
- 54: Divisible by 2, 3, 6, 9, 18 → Not Prime
- 24: Divisible by 2, 3, 4, 6, 8, 12 → Not Prime
- 18: Divisible by 2, 3, 6, 9 → Not Prime
- 96: Divisible by 2, 3, 4, 6, 8, 12, 16, 24, 32, 48 → Not Prime

#### Row 5:
- 71: Only divisible by 1 and 71 → Prime
- 26: Divisible by 2, 13 → Not Prime
- 68: Divisible by 2, 4, 17 → Not Prime
- 20: Divisible by 2, 4, 5, 10 → Not Prime
- 85: Divisible by 5, 17 → Not Prime

#### Row 6:
- 58: Divisible by 2, 29 → Not Prime
- 30: Divisible by 2, 3, 5, 6, 10, 15 → Not Prime
- 76: Divisible by 2, 4, 19 → Not Prime
- 46: Divisible by 2, 23 → Not Prime
- 31: Only divisible by 1 and 31 → Prime

Final List of Prime Numbers:

From the analysis, the prime numbers in the list are:
- 61
- 29
- 79
- 71
- 31

Circled Answer:

The circled prime numbers in the grid would be:
```
70, 65, 25, 16, 90
55, 🟩61, 80, 77, 32
42, 60, 93, 🟩29, 🟩79
56, 54, 24, 18, 96
🟩71, 26, 68, 20, 85
58, 30, 76, 46, 🟩31
```

Final Answer:

\boxed{61, 29, 79, 71, 31}