Equal groups all hold the same number. Three plates with 4 buns each.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Adding the same number again
To find the total, add the group size once for each group: 4 + 4 + 4 = 12.
They really must be equal
If one plate has 5, the groups are not equal, and this shortcut does not apply.
What makes groups equal
Equal groups all hold the same number of things. Three plates with 4 biscuits each is equal groups. Three plates holding 4, 5 and 3 is not — it is just three plates. The word "equal" is doing real work in the phrase and must be checked, not assumed.
Counting them by skip-counting
To count 4 groups of 5, skip-count in fives: 5, 10, 15, 20. This is far faster than counting every object and far less prone to losing your place. Equal groups are exactly the situation skip-counting was built for.
Saying it precisely
Read "4 groups of 5" in that order: four groups, five in each. Four groups of 5 is 20 and five groups of 4 is also 20, but the pictures look different — four plates of five biscuits, or five plates of four. Same total, different arrangement.
Step 2: Try It Yourself
Change the rows and columns, and read the sentence underneath.
4 + 4 + 4 = 12
3 rows of 4 makes 12.
Step 3: Watch an Example
One step at a time.
Watch Ana Count Equal Groups
Ana has 3 plates with 4 buns on each.
- Step 1
She checks that every plate holds the same number. They do.
Step 4: Your Turn
Practice makes it stick.
The Bike Rack
Problem 1 of 2
5 bicycles are in a rack. Each has 2 wheels. How many wheels?
wheels
Packs of Pens
Problem 2 of 2
4 packs each hold 5 pens. How many pens in all?
pens
Add the Groups
1 of 4
3 groups of 5. How many in all?
2 of 4
4 groups of 3. How many in all?
3 of 4
2 groups of 5. How many in all?
4 of 4
One plate has 4 buns and another has 6. Are these equal groups?
Step 5: Quick Check
Show what you know.
Question 1 of 2
5 groups of 4. How many in all?
Question 2 of 2
What must be true of the groups?
What You Learned
- Equal groups all hold the same number.
- Add the group size once for each group.
- If the groups differ, this does not work.