3rd grade · Math · Unit 11 of 14
Times Tens
Multiply by 10, 20, 30 ...
What your child practices
Multiplying a one-digit number by a multiple of ten (like 6 × 40) using a basic fact and place value.
Alaska content standards learning standard: 3.NBT.3 · multiplying one-digit whole numbers by multiples of 10 from 10 to 90
How we explain it
Children can open this short lesson before they practice.
- Use the basic fact first.
- Then multiply by 10: the answer is that many tens.
- 6 × 40 is 6 × 4 tens.
Example: What is 6 × 40? 6 × 4 = 24. 24 tens = 240. Answer: 240
Times Tens in Alaska
In the Alaska content standards, this is unit 11 of 14 in 3rd grade Math, after Sorting Polygons and before Two-Step Stories.
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: Alaska Department of Education and Early Development
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
There are 6 shelves with 40 books in each. How many books are there?
- 270
- 240
- 2400
- 46
- 24
240
Hint: Multiply 6 × 40. Think 6 × 4 tens.
Question 2
What is 3 × 40?
3 × 40 = ?
- 43
- 120
- 1200
- 12
120
Hint: 3 × 4 = 12, so 3 × 4 tens = 12 tens = 120.
Question 3
9 × ? = 630. What number is missing?
- 60
- 40
- 70
- 700
- 80
70
Hint: Think: 9 times how many tens makes 63 tens?
Question 4
9 × 4 = 36. So what is 9 × 40?
- 370
- 36
- 46
- 360
- 3600
360
Hint: 40 is 4 tens. 9 × 4 tens = 36 tens.
Question 5
There are 8 shelves with 50 books in each. How many books are there?
- 58
- 380
- 4000
- 40
- 400
400
Hint: Multiply 8 × 50. Think 8 × 5 tens.
Question 6
5 × 7 = 35. So what is 5 × 70?
- 3500
- 35
- 45
- 350
- 320
350
Hint: 70 is 7 tens. 5 × 7 tens = 35 tens.