2nd grade · Math · Unit 14 of 16
Arrays
Rows and columns
What your child practices
Adding equal rows to find the total in an array (up to 5 by 5), and cutting a rectangle into rows and columns of squares. This gets ready for multiplication.
Maine Learning Results learning standard: 2.OA.C.4; 2.G.A.2 · adding to find the total in rectangular arrays, and partitioning a rectangle into rows and columns of squares
How we explain it
Children can open this short lesson before they practice.
- An array has equal rows.
- Add the same number once for each row.
- This is a first step to multiplying.
Example: 3 rows with 4 in each row. How many in all? 4 + 4 + 4 = 12. Answer: 12
Arrays in Maine
In the Maine Learning Results, this is unit 14 of 16 in 2nd grade Math, after Inches, Feet & Yards and before Add & Subtract to 1000.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Maine Department of Education
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
There are 2 rows with 3 in each row. Which addition finds the total?
🔵🔵🔵🔵🔵🔵- 3 + 3 + 3
- 4 + 4
- 2 + 3
- 3 + 3
3 + 3
Hint: Add one 3 for each of the 2 rows.
Question 2
How many 🌟 are in the array?
🌟🌟🌟🌟🌟🌟🌟🌟- 9
- 12
- 6
- 11
- 8
8
Hint: There are 2 rows of 4. Add: 4 + 4.
Question 3
There are 5 rows in a carton with 4 eggs in each. How many eggs in all?
- 9
- 23
- 20
- 24
20
Hint: Add 4 5 times.
Question 4
A rectangle is cut into 4 rows and 3 columns of same-size squares. How many squares?
- 12
- 14
- 7
- 13
12
Hint: Add 3 for each row: 3 + 3 + 3 + 3.
Question 5
How many 🌼 are in the array?
🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼🌼- 30
- 10
- 25
- 23
- 20
25
Hint: There are 5 rows of 5. Add: 5 + 5 + 5 + 5 + 5.
Question 6
There are 2 rows with 5 in each row. Which addition finds the total?
🔵🔵🔵🔵🔵🔵🔵🔵🔵🔵- 5 + 5
- 6 + 6
- 2 + 5
- 5 + 5 + 5
5 + 5
Hint: Add one 5 for each of the 2 rows.