This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 42, to find which of 3,5,6,7 are factors: systematically check divisibility: 42÷3=14 (yes), 42÷5=8.4 (no), 42÷6=7 (yes), 42÷7=6 (yes). Choice C is correct because it lists 3,6,7 as factors (all divide evenly) and excludes 5, demonstrating systematic factor finding and understanding of prime/composite definitions. Choice D represents including non-factors, which happens when students include numbers that don't divide evenly like 5 (42÷5=8.4). To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.

This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 40, to find which of 5,6,8,10 are factors: check divisibility—40÷5=8 (yes), 40÷6≈6.67 (no), 40÷8=5 (yes), 40÷10=4 (yes). Choice B is correct because it lists all that divide evenly: 5,8,10. This demonstrates systematic factor finding and understanding of prime/composite definitions. Choice D represents including non-factors, which happens when students include numbers that don't divide evenly. To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.

This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 36, to find all factor pairs: systematically check divisibility starting from 1: 1×36, 2×18, 3×12, 4×9, 6×6, and list all unique factors: 1,2,3,4,6,9,12,18,36. Choice A is correct because all factors are listed (checked all numbers 1 through √36=6) and none are missing or extra, demonstrating systematic factor finding and understanding of prime/composite definitions. Choice B represents including non-factors, which happens when students include numbers that don't divide evenly like 8 (36÷8=4.5). To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.

This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 24, to find all factor pairs: systematically check divisibility starting from 1: 1×24, 2×12 if even, 3×8 if divisible, 4×6 if divisible, continuing until factors repeat. Choice B is correct because all pairs are listed (checked all numbers 1 through √24 ≈4.9) and none are missing, including (4,6), which demonstrates systematic factor finding and understanding of prime/composite definitions. Choice A represents missing factor pairs, which happens when students don't check all possible factors systematically. To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.

This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 64, to find all factor pairs: systematically check divisibility starting from 1: 1×64, 2×32, 4×16, 8×8, continuing until factors repeat. Choice A is correct because all pairs are listed (checked all numbers 1 through √64=8) and none are missing. Choice B represents missing factor pairs, which happens when students stop too early. To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.

This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 18, to find all factors: systematically check divisibility starting from 1 up to 18, listing all that divide evenly: 1,2,3,6,9,18. Choice A is correct because all factors are listed (checked all numbers 1 through 18) and none are missing or extra. This demonstrates systematic factor finding and understanding of prime/composite definitions. Choice B represents including non-factors, which happens when students include numbers that don't divide evenly. To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.

This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 45, to find all factors: systematically check divisibility starting from 1 up to √45≈6.7, listing 1,3,5,9,15,45 since they divide evenly. Choice A is correct because all factors are listed (checked all numbers 1 through √45) and none are missing. Choice B represents including non-factors, which happens when students include numbers that don't divide evenly. To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.

This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 36, to find all factors: systematically check divisibility starting from 1 up to 36, listing all that divide evenly: 1,2,3,4,6,9,12,18,36. Choice A is correct because all factors are listed (checked all numbers 1 through 36) and none are missing or extra. This demonstrates systematic factor finding and understanding of prime/composite definitions. Choice B represents including non-factors, which happens when students include numbers that don't divide evenly. To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.

This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 29, to determine prime or composite: count factors—if exactly 2 factors (1 and 29) then prime, if more than 2 then composite. Choice B is correct because the number has exactly 2 factors (only 1 and itself divide evenly), which demonstrates systematic factor finding and understanding of prime/composite definitions. Choice C represents wrong prime/composite determination, which happens when students make division error like thinking 2 divides 29 (29÷2=14.5). To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.

This question tests 4th grade ability to find all factor pairs for whole numbers 1-100, recognize that a number is a multiple of each of its factors, determine if a number is a multiple of a given one-digit number, and determine whether a number is prime or composite (CCSS.4.OA.4). A factor is a whole number that divides another number evenly with no remainder—if a × b = n, then both a and b are factors of n, and (a, b) is a factor pair. To find all factor pairs, systematically check: does 1 divide n? does 2? does 3? and so on up to √n, stopping when factors start repeating. A prime number has exactly 2 factors (1 and itself), while a composite number has more than 2 factors. The number 1 is special—it's neither prime nor composite (only 1 factor). For the number 12, to find all factor pairs: systematically check divisibility starting from 1: 1×12, 2×6, 3×4, and these correspond to rectangular arrays. Choice A is correct because all pairs are listed (checked all numbers 1 through √12≈3.46) and none are missing, demonstrating systematic factor finding and understanding of prime/composite definitions. Choice B represents including non-factors, which happens when students include pairs that don't multiply to 12 like 2×5=10. To help students: For finding factor pairs, use systematic approach—start with 1 (always works), check 2, 3, 4, 5, etc., stop when you start seeing the same pairs reversed. Example for 24: 1×24 ✓, 2×12 ✓, 3×8 ✓, 4×6 ✓, 5 doesn't work, 6×4 (already have 4×6, stop). For prime/composite, count factors: exactly 2 = prime, more than 2 = composite. Remember: 1 is neither (only 1 factor), 2 is only even prime. For multiples, divide: if no remainder, it IS a multiple (48 ÷ 6 = 8 R0 ✓). Use arrays to visualize: 12 objects can arrange as 1×12, 2×6, 3×4—each arrangement shows a factor pair. Connect: if f is a factor of n, then n is a multiple of f (inverse relationship). Watch for: missing factor pairs, including non-factors, calling 1 prime, thinking all odd numbers are prime (9, 15, 21 are composite), confusing factors with multiples, and not checking systematically.