To find the prime numbers in the list, we need to check each number to see if it has exactly two factors: 1 and itself. If a number can be divided evenly by any other number (like 2, 3, or 5), it is not prime.
Here is the step-by-step check for each number in the image:
Row 1:
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18: Even number (divisible by 2). Not prime.
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27: Divisible by 3 ($3 \times 9 = 27$). Not prime.
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23: Cannot be divided by 2, 3, or 5.
Prime.
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8: Even number. Not prime.
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7: Only divisible by 1 and 7.
Prime.
Row 2:
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33: Divisible by 3 ($3 \times 11 = 33$). Not prime.
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39: Divisible by 3 ($3 \times 13 = 39$). Not prime.
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37: Cannot be divided by 2, 3, or 5.
Prime.
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22: Even number. Not prime.
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16: Even number. Not prime.
Row 3:
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3: Only divisible by 1 and 3.
Prime.
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6: Even number. Not prime.
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9: Divisible by 3 ($3 \times 3 = 9$). Not prime.
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5: Only divisible by 1 and 5.
Prime.
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11: Only divisible by 1 and 11.
Prime.
Row 4:
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30: Even number. Not prime.
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41: Cannot be divided by 2, 3, or 5.
Prime.
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36: Even number. Not prime.
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25: Divisible by 5 ($5 \times 5 = 25$). Not prime.
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29: Cannot be divided by 2, 3, or 5.
Prime.
Row 5:
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17: Cannot be divided by 2, 3, or 5.
Prime.
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32: Even number. Not prime.
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38: Even number. Not prime.
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13: Only divisible by 1 and 13.
Prime.
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47: Cannot be divided by 2, 3, or 5.
Prime.
Row 6:
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30: Even number. Not prime.
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38: Even number. Not prime.
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28: Even number. Not prime.
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16: Even number. Not prime.
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40: Even number. Not prime.
Row 7:
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5: Already identified as
Prime.
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25: Divisible by 5. Not prime.
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35: Divisible by 5 ($5 \times 7 = 35$). Not prime.
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45: Ends in 5, so it is divisible by 5. Not prime.
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15: Divisible by 3 and 5. Not prime.
Row 8:
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16: Even number. Not prime.
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4: Even number. Not prime.
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2: The only even prime number.
Prime.
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12: Even number. Not prime.
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18: Even number. Not prime.
The prime numbers found are: 23, 7, 37, 3, 5, 11, 41, 29, 17, 13, 47, 5, and 2.
Final Answer:
The prime numbers to circle are:
2, 3, 5, 7, 11, 13, 17, 23, 29, 37, 41, 47
Parent Tip: Review the logic above to help your child master the concept of prime and composite numbers worksheets.
