5th grade · Math · Unit 2 of 14
Multiply
Multiply up to three digits
What your child practices
Multiplying 2- and 3-digit numbers using area models and partial products, patterns with 10, 100 and 1000, doubling and halving, and estimating products by rounding.
Arizona Academic Standards learning standard: 5.NBT.B.5 · fluently multiplying multi-digit whole numbers
How we explain it
Children can open this short lesson before they practice.
- Break the bigger number into place values.
- Multiply each part, then add the parts together.
- Estimate by rounding to check your answer makes sense.
Example: 23 × 14 = ? 23 × 10 = 230. 23 × 4 = 92. 230 + 92 = 322. Answer: 322
Multiply in Arizona
In the Arizona Academic Standards, this is unit 2 of 14 in 5th grade Math, after Numbers to a Million and before Divide.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Arizona Department of Education
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Which has the same product as 50 × 32?
- 52 × 30
- 50 × 16
- 100 × 64
- 100 × 16
100 × 16
Hint: Doubling one factor and halving the other keeps the product the same. Check that only one factor was doubled and the other was halved.
Question 2
Multiply using a pattern.
117 × 10 = ?
answer box
1170
Hint: Multiply the non-zero parts first, then write all the zeros from the factors on the end.
Question 3
Use the area model. What is 67 × 28?
Area model for 67 × 28 × 60 7 20 1200 140 8 480 56 answer box
1876
Hint: Each box holds a partial product. Add all the partial products inside the model to get the total.
Question 4
An orchard has 81 rows of apple trees with 18 trees in each row. How many trees are there?
answer boxtrees
1458 trees
Hint: Equal groups mean multiply. Split one factor into place-value parts, multiply each part, then add.
Question 5
Multiply.
509 × 9 = ?
answer box
4581
Hint: Split 509 into place-value parts (500 + 9). Multiply each part by 9, then add the partial products.
Question 6
Tickets to a science center cost $12 each. A school buys 23 tickets and also pays $40 for parking. What is the total cost in dollars?
answer box
316
Hint: Step 1: multiply to find the cost of all the items. Step 2: add the extra cost.