Divisibility Rules
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SSAT Middle Level: Quantitative › Divisibility Rules
Identify the number that is NOT divisible by 10.
3,450
6,780
7,001
9,120
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 10 if it ends in 0. In this case, students check the last digit for not ending in 0. Choice C is correct because 7,001 ends in 1, not 0. This demonstrates the student's ability to recognize and apply the rule accurately. Choice A is incorrect because 3,450 ends in 0. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors like confusing with 5.
Identify the number that is NOT divisible by 3.
222
405
517
639
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 3 if the sum of its digits is divisible by 3. In this case, students check the digit sum for each option. Choice C is correct because 517's digit sum is 5+1+7=13, and 13 is not divisible by 3. This demonstrates the student's ability to recognize and apply the rule accurately. Choice A is incorrect because 222's sum is 6, divisible by 3. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors in summing digits.
Which of the following numbers is divisible by 9?
2,718
5,432
1,234
4,563
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 9 if the sum of its digits is divisible by 9. In this case, students calculate the digit sum for each option. Choice C is correct because 4,563's sum is 4+5+6+3=18, and 18 ÷ 9 = 2. This demonstrates the student's ability to recognize and apply the rule accurately. Choice A is incorrect because 1,234's sum is 10, not divisible by 9. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors in digit summing.
Identify the number that is NOT divisible by 2.
1,246
908
731
520
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 2 if its last digit is even. In this case, students check the last digit for oddness to find the one not divisible by 2. Choice B is correct because 731 ends in 1, which is odd. This demonstrates the student's ability to recognize and apply the rule accurately. Choice A is incorrect because 908 ends in 8, even. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors like misidentifying even digits.
Which of the following numbers is divisible by 8?
1,118
1,116
1,114
1,112
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 8 if its last three digits form a number divisible by 8. In this case, students apply the rule for 8 to each option. Choice A is correct because 1,112's last three digits are 112, and 112 ÷ 8 = 14. This demonstrates the student's ability to recognize and apply the rule accurately. Choice B is incorrect because 1,114's last three are 114, and 114 ÷ 8 = 14.25. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors like checking only the last digit.
Which of the following numbers is divisible by 5?
7,221
5,337
4,318
9,640
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 5 if it ends in 0 or 5. In this case, students check the last digit of each number. Choice C is correct because 9,640 ends in 0. This demonstrates the student's ability to recognize and apply the rule accurately. Choice A is incorrect because 4,318 ends in 8, not 0 or 5. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors like overlooking the last digit.
Which of the following numbers is divisible by 4?
1,062
1,096
1,086
1,074
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 4 if its last two digits are divisible by 4. In this case, students check the last two digits of each. Choice D is correct because 1,096's last two are 96, and 96 ÷ 4 = 24. This demonstrates the student's ability to recognize and apply the rule accurately. Choice A is incorrect because 1,062's last two are 62, and 62 ÷ 4 = 15.5. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors in division of last digits.
Which of the following numbers is divisible by 2?
317
601
842
955
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 2 if its last digit is even. In this case, students apply the rule that a number is divisible by 2 if it ends in 0, 2, 4, 6, or 8. Choice B is correct because 842 ends in 2, which is even, confirming it is divisible by 2. This demonstrates the student's ability to recognize and apply the rule accurately. Choice A is incorrect because 317 ends in 7, which is odd. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors like confusing even and odd digits.
Which of the following numbers is divisible by 6?
123
204
215
451
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 6 if it is divisible by both 2 and 3. In this case, students check each number for divisibility by 6. Choice B is correct because 204 is even and its digit sum (2+0+4=6) is divisible by 3. This demonstrates the student's ability to recognize and apply the rule accurately. Choice A is incorrect because 123 is odd, so not divisible by 2. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors like forgetting to check both 2 and 3.
If a number is divisible by 8, what must be true about its digits?
It ends in 0 or 5.
The last three digits are divisible by 8.
The digit sum is divisible by 8.
The last digit is 8.
Explanation
This question tests middle school number properties and integer skills, specifically the understanding and application of divisibility rules. Divisibility rules help determine if one number divides another without a remainder using specific patterns. For example, a number is divisible by 8 if its last three digits form a number divisible by 8. In this case, students recall the rule for 8. Choice A is correct because it accurately states the last three digits rule. This demonstrates the student's ability to recognize and apply the rule accurately. Choice B is incorrect because the last digit alone does not determine divisibility by 8. To help students: Focus on teaching each rule with examples, practice identifying patterns in numbers, and encourage students to verify their answers by applying the rule. Watch for common errors like confusing 8 with 2 or 4.