Math Expressions Grade 2, Unit 7: Array Addition and Equal Shares
In this unit, your child finds totals in arrays by adding equal rows, sorts numbers into odd and even, and splits shapes into equal shares. They cover rectangles with rows of same-size squares and name halves, thirds, and fourths. It builds on three-digit addition and subtraction and lays the groundwork for multiplication and fractions in third grade.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 7?
- Pairing up objects to tell whether a number up to 20 is odd or even, and writing even numbers as doubles. Learn more: Odd and even numbers
- Adding equal rows in arrays up to 5 by 5, like 3 + 3 + 3 + 3 = 12 for 4 rows of 3. Learn more: Counting objects in equal rows by adding
- Covering a rectangle with rows and columns of same-size squares, then counting them row by row. Learn more: Splitting a rectangle into rows of squares
- Cutting circles and rectangles into two, three, or four equal shares, and seeing that two halves or four fourths make a whole. Learn more: Halves, thirds, and fourths of shapes
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
Is 16 an even or odd number?
- Even
- Odd
- Neither
How you can help
- Set out spoons or socks and ask your child to make pairs. If one is left over, the number is odd; if none is left, it is even.
- Line up toy cars or blocks in 4 rows of 3. Ask your child to add the rows, then turn the array and add 3 rows of 4.
- Fold a napkin into fourths, open it up, and count the shares. Ask what each share is called and how many make the whole napkin.
Where kids can get stuck
- Writing an even number as any two numbers, like 12 = 5 + 7, rather than a double like 6 + 6.
- Counting every object in an array one by one instead of adding the rows, and losing count.
- Drawing squares of different sizes when splitting a rectangle, so the rows are not truly equal.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- odd
- A number that has one left over when you make pairs, like 7 or 15.
- even
- A number that splits into pairs with none left over, like 6 or 14.
- array
- Objects set out in equal rows and columns, like eggs in a carton.
- row
- A line of things that goes across.
- column
- A line of things that goes up and down.
- equal shares
- Parts of a whole that are all the same size.
- half
- One of 2 equal shares of a whole.
- third
- One of 3 equal shares of a whole.
- fourth
- One of 4 equal shares of a whole, also called a quarter.
Ready to build your child’s confidence with arrays and equal shares?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
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Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Math Expressions Grade 2 Unit 7 cover?
Math Expressions Grade 2 Unit 7 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
- 2.OA.C.3: Determine whether a group of objects (up to 20) has an odd or even number of members.
- 2.OA.C.4: Use addition to find the total number of objects arranged in rectangular arrays.
- 2.G.A.2: Partition a rectangle into rows and columns of same-size squares.
- 2.G.A.3: Partition circles and rectangles into two, three, or four equal shares.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.