Equal Rows Before Multiplication
A 45-minute Grade 2 lesson on finding the total in a rectangular array by adding equal rows — the last step before multiplication, and the one that makes multiplication make sense.
Equal Rows Before Multiplication is a free 45-minute Grade 2 maths lesson plan for Common Core standard 2.OA.C.4 — add equal rows to find a total — the first step toward multiplication. It is timed across 5 sections, gives the exact wording to use where the wording carries the mathematics, names 3 misconceptions with the teaching move that addresses each, and ends with an exit ticket and a printable worksheet with its answer key.
- Grade:
- Grade 2
- Length:
- 45 minutes
- Standard:
- 2.OA.C.4
Grade 2 · Operations & Algebraic Thinking
2.OA.C.4
Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends.
Objective
Students will be able to find the total of a rectangular array by adding equal addends, and write the equation that matches.
Students are successful when they can
- Counts the rows and the number in each row before adding.
- Writes the repeated addition that matches the array.
- Gets the same total when the array is turned on its side.
What you need
- Counters and squared paper
- Array cards up to 5 by 5
- Egg boxes or muffin trays for a physical array
- The printable practice sheet linked at the end of this plan
The lesson
Warm-up — count the rows
5 min- Show three array cards. For each, ask how many rows and how many in each row. Do not ask for the total.
- Separating the two numbers is the skill; the total comes easily afterwards.
Teach — equal rows add up
13 min- Build a 4 by 3 array with counters. Ask how many rows: four. How many in each: three.
- Count the total by threes: 3, 6, 9, 12.
- Write 3 + 3 + 3 + 3 = 12 and point at each row as you read each addend.
- Ask what would go wrong if one row had four. The addends stop being equal, and repeated addition stops working.
- Turn the array on its side. Now it is 3 rows of 4, written 4 + 4 + 4 = 12. Same counters, same total, different equation.
- Point out that both equations are true and they describe different pictures.
“Every row must have the same number. That is what lets you add the same number again and again instead of counting all of them.”
Guided practice — build, write, turn
12 min- Pairs build an array from a card, write the repeated addition, and find the total.
- They then turn the array and write the second equation.
- Ask which of the two was easier to add, and why. Adding four threes usually beats three fours for these pupils.
Independent practice
12 min- Students complete an equal rows page.
- An equation with unequal addends means the array was miscounted; a correct total with no equation means the counting was one by one.
Close
3 min- Show a 5 by 2 array and collect both equations.
- Ask which number tells you how many rows in each, and stop there.
What goes wrong, and why
Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.
Counts every counter in the array one at a time.
Why: Counting all is reliable and the structure of the array has not yet been noticed as useful. The rows are visible but not being used.
Fix: Cover all but one row and ask how many are in it, then reveal a row at a time while skip counting. The structure gets used because it is all that is available.
Writes 4 + 3 = 12 for a 4 by 3 array.
Why: The two numbers describing the array have been combined with the operation that is being practised, without a check that the equation says anything true.
Fix: Read the equation aloud and check it against the picture. Four plus three is seven, and there are clearly more than seven counters.
Says a turned array is a different total and recounts it.
Why: The picture changed, so the quantity is assumed to have changed. This is conservation again, in a new setting.
Fix: Turn the physical array in front of them without adding or removing a counter. Nothing entered or left, so the total is fixed.
If they are not there yet
- Use arrays with rows of 2, 5 or 10, where the skip count is already fluent and only the structure is new.
- Build in an egg box, where the rows are physically separated and cannot be miscounted.
If they finish early
- Find every array that can be built with 12 counters, and write the equation for each.
- Ask which numbers can be built into more than one array, and which into only one.
- Write the repeated addition as a multiplication and check it gives the same total.
Exit ticket
Draw an array with 3 rows of 5. Write the repeated addition and the total.
What to look for: 15 counters in 3 equal rows, with 5 + 5 + 5 = 15. Rows of different lengths mean the array was drawn to a total rather than to the structure.
Printable practice for 2.OA.C.4
Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.
- Equal Rows — Repeated AdditionWork out each answer.
- Equal Rows — Find the TotalWork out each answer.
Questions about Equal Rows Before Multiplication
How long does the Equal Rows Before Multiplication lesson take?
45 minutes, split across 5 timed sections: warm-up 5 min, teach 13 min, guided practice 12 min, independent practice 12 min, close 3 min. The minutes are stated per section and add up to the stated length, so the plan can be cut or extended at a section boundary rather than abandoned halfway.
Which standard does Equal Rows Before Multiplication teach?
CCSS.MATH.CONTENT.2.OA.C.4 — 2.OA.C.4, Operations & Algebraic Thinking for Grade 2: “Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends.” In plain terms, add equal rows to find a total — the first step toward multiplication.
What do I need to teach this lesson?
Counters and squared paper, array cards up to 5 by 5, egg boxes or muffin trays for a physical array and the printable practice sheet linked at the end of this plan. Everything listed is either ordinary classroom equipment or a free printable from this site — there is nothing to buy and nothing to prepare beyond photocopying.
What mistakes should I expect in this lesson?
Three, each a reasoning error rather than carelessness: counts every counter in the array one at a time; writes 4 + 3 = 12 for a 4 by 3 array and says a turned array is a different total and recounts it. The plan gives the thinking behind each one and the teaching move that addresses the thinking rather than the symptom.
How do I know whether the lesson worked?
The exit ticket asks: “Draw an array with 3 rows of 5. Write the repeated addition and the total.” 15 counters in 3 equal rows, with 5 + 5 + 5 = 15. Rows of different lengths mean the array was drawn to a total rather than to the structure. That tells you whether the class needs a reteach or a thirty-second conversation before you plan tomorrow.
Is there a worksheet to go with Equal Rows Before Multiplication?
Yes — 2 printable 2.OA.C.4 worksheets, linked at the end of the plan and free like the rest of the site. Each one comes with an answer key and 25 versions, so the practice after the lesson can be a different paper on every desk.
Is Equal Rows Before Multiplication free to use?
Yes. The plan, its printables and their answer keys are free to read, print and photocopy for your own class, with no account and no email capture. It was last reviewed on 5 September 2026. Please do not resell it or republish it as your own.
Last reviewed 2026-09-05. Aligned to 2.OA.C.4 of the Common Core State Standards for mathematics.