This grade 3 multiply worksheet answer key solves all 23 problems of the multiplying by multiples of 10 worksheet step by step.
Each solution turns the multiple of 10 into tens, multiplies the basic fact, and then names the product as a number. The final answer is in bold. Compare your steps with these to find where a mistake started.
Grade 3 Multiply Worksheet Answer Key: problems 1–5
Problem 1: Counting tens in rods
There are 4 boxes with 3 tens in each box. \(4 \times 3 = 12\) tens. 12 tens is 120.
Answer: 120
Problem 2: Skip counting by 20
The jumps land on 20, 40, 60, 80. That is \(4 \times 20 = 80\).
Answer: 80
Problem 3: Using a basic fact
40 is 4 tens. 6 groups of 4 tens is 24 tens. 24 tens is 240.
Answer: 240
Problem 4: Multiplying by 30
Think of 30 as 3 tens. Then \(6 \times 3 = 18\), so 6 groups of 3 tens is 18 tens.
18 tens is 180. So \(6 \times 30 = 180\).
Answer: 180
Problem 5: Multiplying by 60
Think of 60 as 6 tens. Then \(5 \times 6 = 30\), so 5 groups of 6 tens is 30 tens.
30 tens is 300. So \(5 \times 60 = 300\).
Answer: 300
Grade 3 Multiply Worksheet Answer Key: problems 6–10
Problem 6: Multiplying by 20
Think of 20 as 2 tens. Then \(7 \times 2 = 14\), so 7 groups of 2 tens is 14 tens.
14 tens is 140. So \(7 \times 20 = 140\).
Answer: 140
Problem 7: Multiplying by 40
Think of 40 as 4 tens. Then \(8 \times 4 = 32\), so 8 groups of 4 tens is 32 tens.
32 tens is 320. So \(8 \times 40 = 320\).
Answer: 320
Problem 8: Multiplying by 80
Think of 80 as 8 tens. Then \(9 \times 8 = 72\), so 9 groups of 8 tens is 72 tens.
72 tens is 720. So \(9 \times 80 = 720\).
Answer: 720
Problem 9: Multiplying by 70
Think of 70 as 7 tens. Then \(3 \times 7 = 21\), so 3 groups of 7 tens is 21 tens.
21 tens is 210. So \(3 \times 70 = 210\).
Answer: 210
Problem 10: Multiplying by 90
Think of 90 as 9 tens. Then \(4 \times 9 = 36\), so 4 groups of 9 tens is 36 tens.
36 tens is 360. So \(4 \times 90 = 360\).
Answer: 360
Grade 3 Multiply Worksheet Answer Key: problems 11–15
Problem 11: Tens first
70 is 7 tens. Switch the order: \(5 \times 70\). \(5 \times 7 = 35\), so 35 tens. 35 tens is 350.
Answer: 350
Problem 12: Missing factor, tens
420 is 42 tens. Think \(6 \times 7 = 42\), so \(6 \times 70 = 420\).
Answer: 70
Problem 13: Missing factor, ones
400 is 40 tens and 50 is 5 tens. Think \(8 \times 5 = 40\), so \(8 \times 50 = 400\).
Answer: 8
Problem 14: Tens in an array
There are \(4 \times 6 = 24\) squares worth 10 each. 24 tens is 240. That matches \(4 \times 60 = 240\).
Answer: 240
Problem 15: Comparing products
\(7 \times 30 = 210\) because \(7 \times 3 = 21\). \(6 \times 40 = 240\) because \(6 \times 4 = 24\).
\(210 < 240\). Answer: 7 × 30 < 6 × 40
Grade 3 Multiply Worksheet Answer Key: problems 16–20
Problem 16: Completing a pattern
\(8 \times 3 = 24\) so \(8 \times 30 = 240\). \(8 \times 6 = 48\) so \(8 \times 60 = 480\). \(8 \times 9 = 72\) so \(8 \times 90 = 720\).
Answer: 240, 480, 720
Problem 17: Finding the mistake
Aisha used the basic fact \(6 \times 5 = 30\) but forgot that 50 is 5 tens. 30 is 30 tens, not 30 ones. 30 tens is 300.
Answer: 6 × 50 = 300
Problem 18: Bags of marbles
\(3 \times 4 = 12\), so 12 tens. 12 tens is 120.
Answer: 120 marbles
Problem 19: Bake sale trays
\(8 \times 2 = 16\), so 16 tens. 16 tens is 160.
Answer: 160 cookies
Problem 20: Little League baseballs
\(9 \times 2 = 18\), so 18 tens. 18 tens is 180.
Answer: 180 baseballs
Grade 3 Multiply Worksheet Answer Key: problems 21–23
Problem 21: Farmers market baskets
- Priya: \(6 \times 30 = 180\) apples.
- Jamal: \(5 \times 40 = 200\) pears.
- \(200 – 180 = 20\).
Answer: Jamal sells 20 more
Problem 22: Road trip miles
- First part: \(7 \times 60 = 420\) miles.
- Second part: \(3 \times 50 = 150\) miles.
- Total: \(420 + 150 = 570\) miles.
Answer: 570 miles
Problem 23: Sticker books
- Stickers bought: \(6 \times 80 = 480\).
- Stickers left: \(480 – 150 = 330\).
Answer: 330 stickers
How to use this grade 3 multiply worksheet answer key
Read this grade 3 multiply worksheet answer key after trying each problem yourself, and redo any problem you missed.
See every chapter on the Grade 3 math page.