Use Arrays to Add Equal Groups - 2nd Grade Math

1. Which two arrays have the same total: $2\times^5$ and $5\times^2$? State the common total.

   $10$. Both arrays have 10 objects total, just arranged differently.

2. What is the total number of objects in a $4\times^3$ array using addition?

   $3+3+3+3=12$. 4 rows with 3 objects each: add 3 four times.

3. What is the total in an array with $3$ rows and $4$ columns, using addition?

   $4+4+4=12$. Add the number in each row (4) three times for 3 rows.

4. What is the total for an array shown by $1+1+1+1$?

   $4$. Four groups of $1$ equals $4$.

5. What is the total number of objects in an array with $1$ row and $4$ columns?

   $4$. One row means just count the columns.

6. What is the total number of objects in a $4\times^1$ array using addition?

   $1+1+1+1=4$. 4 rows with 1 object each: add 1 four times.

7. What is the total number of objects in an array with $3$ rows and $4$ columns?

   $4+4+4=12$. Add $4$ three times for $3$ groups of $4$.

8. What is the total in an array with $5$ rows of $4$ objects each, written as repeated addition?

   $4+4+4+4+4=20$. Each row has 4 objects, so add 4 five times.

9. Find the missing addend: $3+3+3+?=12$ for an array with $4$ equal rows.

   $3$. Four equal addends must sum to 12, so each is 3.

10. Identify what the rows mean in a rectangular array.

    Rows are horizontal lines of objects. Rows go across from left to right.

11. What equation shows the total for an array with $5$ rows and $3$ columns?

    $3+3+3+3+3=15$. Add the number in each row (3) five times for 5 rows.

12. What is a rectangular array in math?

    An arrangement in equal rows and equal columns. Objects organized in equal rows and columns form a grid pattern.

13. What is the total number of objects in an array with $4$ rows and $4$ columns?

    $4+4+4+4=16$. Add $4$ four times for $4$ groups of $4$.

14. Which addition equation matches an array with $5$ rows and $4$ columns?

    $4+4+4+4+4=20$. 5 rows of 4 means add 4 five times.

15. What is the total number of objects in a $3\times^4$ array using addition?

    $4+4+4=12$. 3 rows with 4 objects each: add 4 three times.

16. What is the total in an array with $4$ rows and $3$ columns, using addition?

    $3+3+3+3=12$. Add the number in each row (3) four times for 4 rows.

17. What is the total in an array with $5$ rows and $4$ columns, using addition?

    $4+4+4+4+4=20$. Add the number in each row (4) five times for 5 rows.

18. What is the total in an array with $1$ row and $5$ columns, using addition?

    $5=5$. With only 1 row, just write the number of columns.

19. Find and correct the equation for a $2\times^4$ array: $2+2+2+2=8$.

    $4+4=8$. 2 rows × 4 columns means add 4 twice, not 2 four times.

20. What is the total in an array with $4$ rows of $2$ objects each, written as repeated addition?

    $2+2+2+2=8$. Each row has 2 objects, so add 2 four times.

21. What is the total number of objects in an array with $5$ rows and $5$ columns, written as repeated addition?

    $5+5+5+5+5=25$. Each row has 5 objects, so add 5 five times.

22. Identify the equal addend in the equation $4+4+4$ for an array with equal groups.

    Each addend is $4$. The number being added repeatedly is the addend.

23. What equation shows the total for an array with $3$ rows and $2$ columns?

    $2+2+2=6$. Add the number in each row (2) three times for 3 rows.

24. What equation shows the total for an array with $5$ rows of $2$ objects each?

    $2+2+2+2+2=10$. Add 2 five times, once for each row.

25. Find the missing total: $2+2+2+2+2=?$ for an array with $5$ equal rows.

    $10$. Add 2 five times: $2+2+2+2+2=10$.

26. Identify the missing number: $3+3+3+3+3=\square$ for a $5\times 3$ array.

    $15$. Five groups of 3 equals 15.

27. Which sum shows $3$ rows of $2$ objects each?

    $2+2+2$. Three groups of $2$ means adding $2$ three times.

28. What is the total in an array with $1$ row of $5$ objects, written as an equation?

    $5=5$. One row of 5 objects equals 5.

29. What is the total in an array with $2$ rows of $5$ objects each, written as repeated addition?

    $5+5=10$. Each row has 5 objects, so add 5 two times.

30. Find and correct the equation for $2$ rows of $4$: $2+2+2+2=8$.

    $4+4=8$. Should show $2$ groups of $4$, not $4$ groups of $2$.

31. What does the word "array" mean in math?

    An arrangement of objects in equal rows and equal columns. Objects form a rectangular pattern with equal spacing.

32. What is the total in an array with $4$ rows of $5$ objects each, written as repeated addition?

    $5+5+5+5=20$. Each row has 5 objects, so add 5 four times.

33. What addition equation matches an array with $4$ rows of $3$ objects each?

    $3+3+3+3=12$. Add $3$ four times for $4$ groups of $3$.

34. Identify the missing addend: $\square+\square+\square+\square=16$ for a $4\times 4$ array.

    $4$. Four equal groups must sum to 16, so each group is 4.

35. What is the total in an array with $3$ rows of $5$ objects each, written as repeated addition?

    $5+5+5=15$. Each row has 5 objects, so add 5 three times.

36. Identify the missing number: $3+3+3+3=\square$.

    $12$. Four groups of $3$ equals $12$.

37. Find and correct the equation for $3$ rows of $4$: $3+3+3+3=12$.

    Correct: $4+4+4=12$. 3 rows of 4 means three 4s, not four 3s.

38. Which repeated-addition equation matches a $3\times^2$ array (3 rows, 2 columns)?

    $2+2+2=6$. 3 rows with 2 objects each: add 2 three times.

39. What is the total in an array with $3$ rows of $3$ objects each, written as repeated addition?

    $3+3+3=9$. Each row has 3 objects, so add 3 three times.

40. What equation shows the total for an array with $2$ rows and $4$ columns?

    $4+4=8$. Add the number in each row (4) twice for 2 rows.

41. Find and correct the equation for a $4\times^2$ array: $4+4=8$.

    $2+2+2+2=8$. 4 rows × 2 columns means add 2 four times, not 4 twice.

42. What is the total in an array with $3$ rows of $4$ objects each, written as repeated addition?

    $4+4+4=12$. Each row has 4 objects, so add 4 three times.

43. Which equation matches an array with $3$ rows and $3$ columns?

    $3+3+3=9$. Three rows of 3 objects each equals 9 total.

44. What equation shows the total in an array with $5$ rows of $2$ objects each?

    $2+2+2+2+2=10$. Add $2$ five times for $5$ rows.

45. What addition equation matches an array with $5$ rows of $2$ objects each?

    $2+2+2+2+2=10$. Add $2$ five times for $5$ groups of $2$.

46. What is the missing number in $4+4+4=\square$ for an array of $3$ rows of $4$?

    $12$. Three groups of $4$ equals $12$.

47. What is the total number of objects in a $2\times^5$ array using addition?

    $5+5=10$. 2 rows with 5 objects each: add 5 two times.

48. What is the total in an array with $4$ rows of $3$ objects each, written as repeated addition?

    $3+3+3+3=12$. Each row has 3 objects, so add 3 four times.

49. Identify what the columns mean in a rectangular array.

    Columns are vertical lines of objects. Columns go up and down.

50. What is the total in an array with $3$ rows and $5$ columns, using addition?

    $5+5+5=15$. Add the number in each row (5) three times for 3 rows.

51. What equation shows the total for an array with $4$ rows and $5$ columns?

    $5+5+5+5=20$. Add the number in each row (5) four times for 4 rows.

52. What equation shows the total for an array with $5$ rows and $1$ column?

    $1+1+1+1+1=5$. Add 1 five times, once for each row.

53. What is the total in an array with $2$ rows and $3$ columns, using addition?

    $3+3=6$. Add the number in each row (3) twice for 2 rows.

54. What equation shows the total in an array with $2$ rows of $5$ objects each?

    $5+5=10$. Add $5$ twice for $2$ rows.

55. What is the total number of objects in an array with $1$ row and $5$ columns?

    $5=5$. One row means just one group of $5$.

56. Identify the missing number: $5+5+5=\square$.

    $15$. Three groups of $5$ equals $15$.

57. Find and correct the equation for $5$ rows of $3$: $5+5+5=15$.

    $3+3+3+3+3=15$. Should show $5$ groups of $3$, not $3$ groups of $5$.

58. Which equation shows $4$ rows of $5$: $5+5+5+5$ or $4+4+4+4+4$?

    $5+5+5+5$. Four groups of $5$ matches $4$ rows with $5$ in each.

59. Identify the number of addends in $3+3+3+3+3$ for a rectangular array equation.

    $5$ addends. Count how many 3s are being added together.

60. What is the total number of objects in a $5\times^2$ array using addition?

    $2+2+2+2+2=10$. 5 rows with 2 objects each: add 2 five times.

61. Find and correct the equation for $4$ rows of $2$: $4+4=8$.

    Correct: $2+2+2+2=8$. Four rows of $2$ means adding $2$ four times, not $4$ twice.

62. What is the total in an array with $4$ rows and $5$ columns, using addition?

    $5+5+5+5=20$. Add the number in each row (5) four times for 4 rows.

63. What addition equation matches an array with $2$ rows and $3$ columns?

    $3+3=6$. Add $3$ twice for $2$ groups of $3$.

64. What is the total number of objects in a $1\times^4$ array using addition?

    $4=4$. 1 row with 4 objects: just write 4 once.

65. Which equation shows $5$ columns of $4$: $4+4+4+4+4$ or $5+5+5+5$?

    $4+4+4+4+4$. Five groups of $4$ matches $5$ columns with $4$ in each.

66. What is the meaning of "rows" in a rectangular array?

    Horizontal lines of objects in the array. Rows go across from left to right.

67. What is the total in an array with $5$ rows of $2$ objects each, written as repeated addition?

    $2+2+2+2+2=10$. Each row has 2 objects, so add 2 five times.

68. Which repeated-addition equation matches a $2\times^3$ array (2 rows, 3 columns)?

    $3+3=6$. 2 rows with 3 objects each: add 3 two times.

69. What is the total in an array with $5$ rows and $5$ columns, using addition?

    $5+5+5+5+5=25$. Add the number in each row (5) five times for 5 rows.

70. What repeated-addition equation matches an array with $2$ columns and $3$ rows?

    $2+2+2=6$. Add column count for each row: $2$ per row, $3$ rows.

71. What is the total in an array with $2$ rows of $4$ objects each, written as repeated addition?

    $4+4=8$. Each row has 4 objects, so add 4 two times.

72. What is the total in an array with $5$ rows of $1$ object each, written as repeated addition?

    $1+1+1+1+1=5$. Each row has 1 object, so add 1 five times.

73. What is the total number of objects in an array with $2$ rows and $5$ columns?

    $5+5=10$. Add $5$ twice for $2$ groups of $5$.

74. What equation shows the total for an array with $3$ rows and $4$ columns?

    $4+4+4=12$. Add the number in each row (4) three times for 3 rows.

75. Which sum shows $4$ columns of $5$ objects each?

    $5+5+5+5$. Four groups of $5$ means adding $5$ four times.

76. What is the total number of objects in an array with $5$ rows and $4$ columns?

    $4+4+4+4+4=20$. Add $4$ five times for $5$ groups of $4$.

77. What is the total number of objects in a $5\times^5$ array using addition?

    $5+5+5+5+5=25$. 5 rows with 5 objects each: add 5 five times.

78. Identify the total for an array with $5$ rows and $4$ columns using addition.

    $4+4+4+4+4=20$. 5 rows with 4 objects each: add 4 five times.

79. Find the missing total: $3+3+3+3=\square$.

    $12$. Four 3s added together equals 12.

80. What repeated-addition equation matches an array with $3$ columns and $2$ rows?

    $3+3=6$. Add column count for each row: $3$ per row, $2$ rows.

81. What is the total number of objects in an array with $5$ rows and $1$ column?

    $1+1+1+1+1=5$. Add $1$ five times for $5$ groups of $1$.

82. Which addition equation matches an array with $4$ rows and $5$ columns?

    $5+5+5+5=20$. 4 rows of 5 means add 5 four times.

83. What equation shows the total in an array with $4$ rows of $3$ objects each?

    $3+3+3+3=12$. Add $3$ four times for $4$ rows.

84. What is the total for an array shown by $2+2+2+2+2$?

    $10$. Five groups of $2$ equals $10$.

85. What equation shows the total for an array with $2$ rows and $5$ columns?

    $5+5=10$. Add 5 twice, once for each row.

86. What addition equation matches an array with $3$ rows of $5$ objects each?

    $5+5+5=15$. Add $5$ three times for $3$ groups of $5$.

87. Find the missing addend: $\square+\square+\square+\square+\square=15$ with equal addends.

    $3$. Five equal groups totaling 15 means each group is 3.

88. Identify the total for an array with $4$ rows and $5$ columns using addition.

    $5+5+5+5=20$. 4 rows with 5 objects each: add 5 four times.

89. What is the total in an array with $4$ rows and $2$ columns, using addition?

    $2+2+2+2=8$. Add the number in each row (2) four times for 4 rows.

90. Find the missing number: $3+3+3+3+3=\square$ for an array with $5$ rows of $3$.

    $15$. Five groups of $3$ equals $15$.

91. What is the meaning of "columns" in a rectangular array?

    Vertical lines of objects in the array. Columns go up and down.

Study these flashcards