An equal-groups story has three numbers: how many groups, how many in each, and the total.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
When to multiply
If you know the groups and the size, and the total is missing, multiply.
When to divide
If you know the total and one of the others, divide.
Draw it first
Sketch the array. The gap in the picture tells you which operation to use.
Step 2: Try It Yourself
Tap and try it out.
7 + 7 + 7 + 7 + 7 + 7 = 42
6 × 7 = 42
42 ÷ 6 = 742 ÷ 7 = 6
6 rows of 7 makes 42.
6 × 7 = 42. 6 and 7 are a factor pair of 42.
Pairs you have found
- 6 × 7
Step 3: In Real Life
Planning a party
36 cookies, 4 to a bag: division tells you 9 bags. 9 bags of 4: multiplication tells you 36 cookies. Same party, and the story tells you which sum.
Step 4: Watch an Example
One step at a time.
Watch Leo Choose
"42 pencils are shared equally between 6 pots."
- Step 1
He finds the total: 42 pencils.
Step 5: Your Turn
Practice makes it stick.
The Bookshelf
Problem 1 of 3
8 shelves each hold 5 books. How many books altogether?
books
The Cupcakes
Problem 2 of 3
36 cupcakes go equally into 4 boxes. How many in each box?
cupcakes
The Teams
Problem 3 of 3
30 children make teams of 5. How many teams are there?
teams
Multiply or Divide?
1 of 4
"7 bags with 4 apples each. How many apples?"
2 of 4
7 bags with 4 apples each. How many apples?
3 of 4
45 sweets shared between 9 children. How many each?
4 of 4
24 chairs in rows of 6. How many rows?
Build the Array
Build it, then check.
Build 6 rows of 7.
1 = 1
1 row of 1 makes 1.
Step 6: Quick Check
Show what you know.
Question 1 of 2
5 boxes with 8 pens each. How many pens?
Question 2 of 2
The total is known and the group size is missing. What do you do?
What You Learned
- Find the three numbers: groups, size, and total.
- Total missing means multiply.
- Total known means divide.
For the grown-up
This lesson is where the child chooses between multiplication and division for equal-group word problems within 100. Multiplication is equal groups before it is a fact to recall. Three fours is three groups of four, and division is the same picture asked from the other end.
Watch for multiplication and division being learned as separate subjects. They are one relationship, and a child who sees that halves what there is to remember.
When they are stuck on a division, ask the multiplication instead: "what times 4 gives 24?" Nearly every child can answer that when they cannot answer 24 divided by 4.
Deciding between multiplying and dividing — If the story gives you the number of groups and the size of each group, multiply to find the total. If it gives you the total and one of the two, divide to find the other. Write down which numbers you have been given and which you have been asked for; the operation follows from that.
Draw the groups, or the array — A quick sketch of 4 circles with 6 dots in each settles almost any confusion. If the drawing has too many things to sketch, draw four boxes labeled 6 instead. The point is to see the structure, not to count.
Check the size of the answer — Multiplying by a whole number bigger than one makes things bigger; dividing makes them smaller. If a story about sharing produces an answer bigger than the total you started with, you have divided the wrong way round. This check takes a second and catches the most common error in the chapter.
What is the story asking for? — "4 bags, 6 apples in each. How many apples?" You know the groups and the size. Multiply. 24 "24 apples in 4 bags. How many in each?" You know the total. Divide. 6 "24 apples, 6 in each bag. How many bags?" Also divide. 4 Ask which number is missing. That decides the operation.