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Divisibility is the ability to divide into a number with no remainder.
The rule for 2 is all even numbers (ending in 0, 2, 4, 6, or 8) are divisible by 2.
3's rule: add up all of the digits and check to see if the answer is a multiple of 3. If so, it is divisible by 3.
5's rule: ends in a zero or 5. 2: Is it even? 3: sum-of-the-digits divisible by 3 5: ends in 5 or zero
Ex: 36
Yes for 2 as it ends in an even digit
Yes for 3 as 3 + 6 = 9 and 9 is a multiple of 3
No for 5 as it ends in a 6 versus a 5 or zero
Now you try! 2: Is it even? Yes, it ends in a 2, 4, 6, 8 or zero No, it ends in an odd number 24 2: Is it even? Yes No 35 2: Is it even? Yes No 144 3: sum-of-the-digits divisble by 3? (Add up the digits before deciding. 3 + 5 = Is it divisible by 3? Yes, it totals to 3, 6, 9, 12, 15... No, its sum is not a multiple of 3 35 3: sum-of-the-digits divisble by 3? (Add up the digits before deciding. 4 + 8 = Is it divisible by 3? Yes No 48 3: sum-of-the-digits divisble by 3? (Add up the digits before deciding. 4 + 5 = Is it divisible by 3? Yes No 45 3: sum-of-the-digits divisble by 3? (Add up the digits before deciding. 2 + 7 = Is it divisible by 3? Yes No 27 3: sum-of-the-digits divisble by 3? (Add up the digits before deciding. 4 + 2 = Is it divisible by 3? Yes No 42 3: sum-of-the-digits divisble by 3? (Add up the digits before deciding. 1+2+3 = Is it divisible by 3? Yes No 123 3: sum-of-the-digits divisble by 3? (Add up the digits before deciding. 5 + 1 = Is it divisible by 3? Yes No 51 3: sum-of-the-digits divisble by 3? (Add up the digits before deciding. 2 + 1 = Is it divisible by 3? Yes No 21 5: ends in a 5 or zero Is it divisible by 5? Yes, it ends in a 5 or zero. No, it does not end in a 5 or zero. 35 5: ends in a 5 or zero Is it divisible by 5? Yes No 120 5: ends in a 5 or zero Is it divisible by 5? Yes No 42 5: ends in a 5 or zero Is it divisible by 5? Yes No 50 5: ends in a 5 or zero Is it divisible by 5? Yes No 24 Both divisible by 2: both even Both divisible by 3: both sums-of-the-digits are divisible by 3 Both divisible by 5: both number end in 5 or zero To simplify fractions find a number both numerator and denominator are divisible by. 6 9 Both divisible by 2: both even Both divisible by 3: both sums-of-the-digits are divisible by 3 Both divisible by 5: both number end in 5 or zero To simplify fractions find a number both numerator and denominator are divisible by. 15 5 Both divisible by 2: both even Both divisible by 3: both sums-of-the-digits are divisible by 3 Both divisible by 5: both number end in 5 or zero To simplify fractions find a number both numerator and denominator are divisible by. 10 24 Both divisible by 2: both even Both divisible by 3: both sums-of-the-digits are divisible by 3 Both divisible by 5: both number end in 5 or zero To simplify fractions find a number both numerator and denominator are divisible by. 10 14 Both divisible by 2: both even Both divisible by 3: both sums-of-the-digits are divisible by 3 Both divisible by 5: both number end in 5 or zero To simplify fractions find a number both numerator and denominator are divisible by. 10 6 Both divisible by 2: both even Both divisible by 3: both sums-of-the-digits are divisible by 3 Both divisible by 5: both number end in 5 or zero To simplify fractions find a number both numerator and denominator are divisible by. 4 6 Both divisible by 2: both even Both divisible by 3: both sums-of-the-digits are divisible by 3 Both divisible by 5: both number end in 5 or zero To simplify fractions find a number both numerator and denominator are divisible by. 40 15 |