🔢 MathGrade 2Lesson 18
← Back🔒 PDF with full access

Make Equal Groups

Lesson preview: the Mini Lesson and Vocabulary are open to everyone. Guided practice, exercises, the parent checklist and the printable PDF worksheet come with full access (free 7-day trial or membership).

Learning Objectives

  • 1Decide whether a set of groups is equal or unequal
  • 2Explain why equal groups are needed for repeated addition
  • 3Write a repeated addition sentence for any equal-group picture
📘

Mini Lesson

In Lesson 17 we used equal groups to write repeated addition sentences. But what makes a group equal — and how do you spot one?

Equal groups

  • Groups are equal when every group contains exactly the same number of objects.
  • Example: Three bags each holding 4 apples → equal groups of 4. You can write 4 + 4 + 4 = 12.
  • Real-life equal groups: rows of chairs, egg cartons, packs of crayons.

Unequal groups

  • Groups are unequal when at least one group has a different number from the others.
  • Example: Three bags holding 4, 3, and 5 apples → unequal groups. You cannot write a repeated addition sentence.
  • You can still add them (4 + 3 + 5 = 12), but it is not repeated addition.

How to check

  • Count the objects in each group separately.
  • Compare the counts — are they all the same number?
  • If every count matches, they are equal groups. If any count differs, they are unequal.
Equal groups versus unequal groupsLeft panel: three boxes each containing 4 dots labeled Equal groups, 4+4+4=12. Right panel: three boxes containing 4, 3, and 5 dots labeled Unequal groups, cannot use repeated addition.Equal vs UnequalEqualUnequal4444 + 4 + 4 = 124354 + 3 + 5 — not equalHow to check:1. Count each group separately.2. Are all the counts the same?3. Yes = equal. No = unequal.
Left — three equal groups of 4 with the repeated addition 4+4+4=12. Right — unequal groups of 4, 3, and 5 that cannot form a repeated addition.
Real-life examples of equal groupsFour panels: 3 groups of 4 = 12, 2 groups of 5 = 10, 4 groups of 3 = 12, and 2 groups of 6 = 12.Equal Groups in Real Life3 groups of 4= 122 groups of 5= 104 groups of 3= 122 groups of 6= 12
Four everyday equal-group sets — 3 of 4, 2 of 5, 4 of 3, and 2 of 6 — each with its total.
💡

Ask yourself: "Does every group have exactly the same number? If yes, they are equal groups!"

Vocabulary
Equal groups
Groups that all have the same number of itemse.g. Three bags of four apples are equal groups.
Unequal groups
Groups that do not all have the same number of itemse.g. Bags of 4, 3, and 5 apples are unequal.
Group
A set of items collected togethere.g. Each group has the same number of crayons.
Repeated addition
Adding the same number over and overe.g. Equal groups let you write a repeated addition sentence.
Total
The amount when you add all groups togethere.g. The total of three equal groups of 5 is 15.
Free · 7 days · No credit card

Unlock the full HSEA system for 7 days.

Add your first kid profile and your 7 days start: every lesson in every grade, saved progress for each child. Nothing to set up, no card required, nothing to cancel.

  • ✓ All 1,680 lessons, Grades 1–6, every subject
  • ✓ Profiles + saved progress for every kid
  • ✓ Printable lessons with answer key
Start your 7-day free trial →
Already convinced? See full membership plans →
← Lesson 17: Learn Concept of Repeated AdditionLesson 19: Understand Multiplication as Groups →