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Here are some tips for Prime Factoring, which aligns with Hawaii state standards:
Prime Factoring
Here are some divisibility rules that should help: Divisibility by 2: If the number ends in 0,2,4,6, or 8, it is divisible by 2. Divisibility by 3: If the sum of the digits is divisible by 3, the number is divisible by 3. Example: 27 is divisible by 3 because 2 + 7 = 9, which is divisible by 3. Divisibility by 5: If the number ends in 0 or 5, it is divisible by 5. Factoring example 1: Factor 24: 24 is divisible by 2, so we now have 2*12 12 is divisible by 2, so we now have 2*2*6 6 is divisible by 2, so we now have 2*2*2*3, which is the final answer. Factoring example 2: Factor 47: 47 is not divisible by 2 because it is not an even number. 47 is not divisible by 3 because 4+7=11 is not divisible by 3 47 is not divisible by 5 because it does not end in 0 or 5 47 is not divisible by 7 because we know that 7*6=42 and 7*7=49 Therefore, 47 is a prime number, so our answer is simply 47. Factoring example 3: Factor 117: 111 is divisible by 3 because 1+1+1=3, which is divisible by 3, giving us 3*39 39 is also divisible by 3, so we now have 3*3*13, which is our final answer. List of prime numbers up to 150: If you want to be really fast at factoring, you might want to memorize these numbers: 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, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149
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