To find the prime numbers from 1 to 100, we need to check each number to see if it has exactly two factors: 1 and itself.
Step 1: Understand the rules
- The number
1 is not a prime number because it only has one factor (itself).
- Even numbers greater than 2 are not prime because they can be divided by 2.
- We only need to "tick" the numbers that cannot be divided evenly by any other number except 1 and themselves.
Step 2: Go through the numbers
*
1–10:
* 1: Not prime.
* 2: Prime (only even prime).
* 3: Prime.
* 4: Not prime ($2 \times 2$).
* 5: Prime.
* 6: Not prime ($2 \times 3$).
* 7: Prime.
* 8, 9, 10: Not prime.
* *Primes found:* 2, 3, 5, 7
*
11–20:
* 11: Prime.
* 12: Not prime.
* 13: Prime.
* 14, 15, 16: Not prime.
* 17: Prime.
* 18: Not prime.
* 19: Prime.
* 20: Not prime.
* *Primes found:* 11, 13, 17, 19
*
21–30:
* 21 ($3 \times 7$), 22, 24, 25 ($5 \times 5$), 26, 27 ($3 \times 9$), 28, 30 are not prime.
* 23: Prime.
* 29: Prime.
* *Primes found:* 23, 29
*
31–40:
* 31: Prime.
* 32, 33 ($3 \times 11$), 34, 35 ($5 \times 7$), 36, 38, 39 ($3 \times 13$), 40 are not prime.
* 37: Prime.
* *Primes found:* 31, 37
*
41–50:
* 41: Prime.
* 42, 44, 45, 46, 48, 49 ($7 \times 7$), 50 are not prime.
* 43: Prime.
* 47: Prime.
* *Primes found:* 41, 43, 47
*
51–60:
* 51 ($3 \times 17$), 52, 54, 55, 56, 57 ($3 \times 19$), 58, 60 are not prime.
* 53: Prime.
* 59: Prime.
* *Primes found:* 53, 59
*
61–70:
* 61: Prime.
* 62, 63, 64, 65, 66, 68, 69, 70 are not prime.
* 67: Prime.
* *Primes found:* 61, 67
*
71–80:
* 71: Prime.
* 72, 74, 75, 76, 77 ($7 \times 11$), 78, 80 are not prime.
* 73: Prime.
* 79: Prime.
* *Primes found:* 71, 73, 79
*
81–90:
* 81 ($9 \times 9$), 82, 84, 85, 86, 87 ($3 \times 29$), 88, 90 are not prime.
* 83: Prime.
* 89: Prime.
* *Primes found:* 83, 89
*
91–100:
* 91 ($7 \times 13$), 92, 93, 94, 95, 96, 98, 99, 100 are not prime.
* 97: Prime.
* *Primes found:* 97
Step 3: Answer the question at the bottom
The worksheet asks: "What are prime numbers?"
A prime number is a whole number greater than 1 that has exactly two factors: 1 and itself.
Final Answer:
Prime Numbers to Tick:
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
Definition for the bottom line:
Prime numbers are numbers greater than 1 that have only two factors: 1 and the number itself.
Parent Tip: Review the logic above to help your child master the concept of worksheet on prime.
