It looks like you've uploaded an image of a
"Prime Numbers Chart" that displays numbers from 1 to 100, with prime numbers highlighted in blue. The chart also includes a note at the bottom:
> "A prime number has exactly two factors: 1 and the number itself."
Let’s go through what this means and how to interpret the chart.
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🔍 What is a Prime Number?
A
prime number is a natural number greater than 1 that has
exactly two distinct positive divisors:
- 1
- The number itself
For example:
- 2 is prime (divisible only by 1 and 2)
- 3 is prime (divisible only by 1 and 3)
- 4 is
not prime (divisible by 1, 2, and 4 → three factors)
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✔ Prime Numbers Between 1 and 100
From your chart, the blue-highlighted numbers are the primes. Let's list them:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97
There are
25 prime numbers between 1 and 100.
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✘ Why Some Numbers Are Not Prime
-
1 is
not a prime number because it has only
one factor (itself), not two.
-
Even numbers (except 2) are not prime because they are divisible by 2.
-
Numbers ending in 5 or 0 (like 5, 15, 25, etc.) are divisible by 5, so they’re not prime unless they're 5 itself.
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🧠 How to Use This Chart
This chart helps identify:
- Which numbers are prime (blue boxes)
- Which are composite (non-blue, >1, not prime)
- Helps students learn divisibility rules
- Great for factoring practice
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🎯 Example Problem (If You Had One)
Since no specific question was asked, here's a common type of problem that might be associated with this chart:
>
Question: List all prime numbers between 50 and 80.
>
Answer: From the chart:
>
53, 59, 61, 67, 71, 73, 79
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✔ Summary
- Prime numbers have
only two factors: 1 and themselves.
- The chart highlights all primes from 1 to 100.
- There are
25 primes in this range.
- Useful for understanding number theory, factoring, and math fundamentals.
If you have a
specific task related to this chart (e.g., “find the sum of all primes less than 50” or “identify composite numbers”), please let me know and I’ll solve it step-by-step!
Parent Tip: Review the logic above to help your child master the concept of composite and prime numbers worksheet.
