3rd Grade Math Quiz: Multiply By Multiples Of 10

20 questions · exam conditions

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Multiply By Multiples Of 10Question 1 of 20

A school cafeteria serves lunch to students in groups. If 7 groups of 40 students each eat lunch, and then 3 more groups of 40 students each eat lunch, what is the total number of students who ate lunch?

280

students total

400

students total

320

students total

120

students total

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3rd Grade Math Quiz

3rd Grade Math Quiz: Multiply By Multiples Of 10

Practice Multiply By Multiples Of 10 in 3rd Grade Math with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Multiply By Multiples Of 10, giving you a quick way to practice the rules, question types, and explanations that matter most for 3rd Grade Math.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

$280$ students total
$400$ students total (correct answer)
$320$ students total
$120$ students total

Explanation: First group:

7 \times 40 = 280

students. Second group:

3 \times 40 = 120

students. Total:

280 + 120 = 400

students. Choice A shows only the first group, choice C shows

8 \times 40

, and choice D shows only the second group.

Question 2

What is $7 \times 30$ ?

21
210 (correct answer)
70
37

Explanation: Multiplying 7 by 30 gives 210, since

7 \times 3 = 21

and then multiplying by 10 gives 210. Choice A (21) is the result of

7 \times 3

without accounting for the extra ten. Choice C (70) mixes up the factors, treating it like

7 \times 10

. Choice D (37) comes from adding 7 and 30 instead of multiplying.

Question 3

If $4 \times 3 = 12$ , what is $4 \times 300$ ?

12000
120
1200 (correct answer)
12

Explanation: 1200 is correct because

4 \times 300 = 1200

. 12000 is incorrect; it has an extra zero, ten times too many. 120 is incorrect because it's the result of

4 \times 30

, one zero short of the correct product. 12 is incorrect; it's just the given fact restated, without scaling up by 100.

Question 4

A coach gives 6 players 40 points each. How many points total?

24 points
240 points (correct answer)
60 points
46 points

Explanation: Multiplying 6 players by 40 points each gives 6 times 40, which is 240 points total. Choice A, 24 points, comes from multiplying 6 by 4 and dropping a zero. Choice C, 60 points, is not the product of 6 and 40. Choice D, 46 points, comes from adding 6 and 40 instead of multiplying.

Question 5

Tessa is packing gift bags. She fills 8 bags with 30 stickers each. Then she realizes she also needs 6 bags with 20 stickers each. How many stickers does Tessa need in all?

$240$
$360$ (correct answer)
$280$
$420$

Explanation: When a word problem describes two separate groups being combined, your plan should be: find the total of each group first, then add those totals together. Watch for the word "also" — it's a clue that you need to combine, not compare. Here, Tessa fills 8 bags with 30 stickers each, so that group needs

8 \times 30 = 240

stickers. Then she needs 6 more bags with 20 stickers each, which is

6 \times 20 = 120

stickers. Adding both groups:

240 + 120 = 360

stickers in all, which matches B. Choice A (240) is only the stickers for the first set of bags — you'd get this if you forgot to add the second group. Choice C (280) comes from a mix-up like

8 \times 20 + 6 \times 20 = 160 + 120

, using the wrong number of stickers for the first group. Choice D (420) results from swapping the stickers-per-bag between the two groups:

8 \times 30 + 6 \times 30

8 \times 20 \times \text{something}

— essentially applying the wrong sticker count and over-counting. A helpful strategy: underline each pair of numbers that "go together" in the problem (8 bags with 30, 6 bags with 20) before multiplying. This keeps you from accidentally pairing the wrong numbers. And always ask yourself, "Am I being asked for a part or the whole?" Here, "in all" signals the whole, so you must add both products.

Question 6

A bus can carry 50 students. Ms. Kim needs to take 265 students on a field trip. If she uses 5 buses, how many students will NOT get a seat?

$50$
$25$
$15$ (correct answer)
$10$

Explanation: Word problems like this one test two skills at once: multiplication (to find total capacity) and subtraction (to find the difference). When you see a "how many are left over" or "how many won't fit" question, think of it as a two-step problem: first find how much space you have, then compare it to how much you need. Start by finding the total number of seats on 5 buses. Since each bus holds 50 students, multiply:

5 \times 50 = 250

seats. Ms. Kim has 265 students but only 250 seats, so subtract to find how many are left without a seat:

265 - 250 = 15

. That matches choice C. Choice A (

50

) is the number of students one whole bus holds — a trap if you forgot to subtract. Choice B (

25

) is what you'd get if you accidentally used only 4 buses (

4 \times 50 = 200

, then miscalculated) or mixed up the numbers. Choice D (

10

) is a common careless-subtraction error — students sometimes compute

265 - 255

or misalign the digits. A good habit for these "leftover" problems: write out both numbers clearly before subtracting — the total capacity and the total people. Line them up vertically to avoid slip-ups. And always ask yourself, "Does my answer make sense?" If 5 buses hold 250 and you have 265 students, only a small number should be left over — so a large answer like 50 should immediately look suspicious.

Question 7

A number multiplied by 60 gives 480. What is the number?

$8$ (correct answer)
$7$
$9$
$80$

Explanation: When you see a problem like "a number multiplied by 60 gives 480," you're really being asked to solve a missing factor problem:

? \times 60 = 480

. The fastest way to find a missing factor in multiplication is to use its inverse operation — division. So you can rewrite the problem as

480 \div 60 = ?

. To divide

480

60

, think of it as

48 \div 6

, since both numbers have a zero you can temporarily ignore. Because

6 \times 8 = 48

, you know

60 \times 8 = 480

. That makes A)

8

the correct answer. Now look at the distractors. B)

7

is wrong because

60 \times 7 = 420

, not

480

— this trap catches students who guess a number close to the answer without checking. C)

9

is wrong because

60 \times 9 = 540

, which overshoots

480

. D)

80

is a classic trap: students see the zeros in

480

and

60

and mistakenly divide

480

6

instead of by

60

, getting

80

. But

60 \times 80 = 4{,}800

, which is ten times too big. A helpful strategy: whenever a multiplication problem gives you the product and one factor, flip it into a division problem to find the missing factor. And always double-check by multiplying your answer back — if

8 \times 60 = 480

, you know you're right.

Question 8

Which number makes this equation true? $? \times 40 = 320$

$7$
$80$
$8$ (correct answer)
$9$

Explanation: When you see a missing-factor problem like

? \times 40 = 320

, think of it as a division question in disguise. If you know that a number times 40 equals 320, then

320 \div 40

will give you that missing number. To solve

320 \div 40

, you can use a helpful shortcut: drop a zero from both numbers to make it easier. That turns the problem into

32 \div 4 = 8

. You can check by multiplying back:

8 \times 40 = 320

. ✓ That confirms C is correct. Now look at the traps. Choice A,

7

, would give

7 \times 40 = 280

, which is too small. Choice B,

80

, is a classic trap — students see the 8 in the answer and add an extra zero, but

80 \times 40 = 3{,}200

, which is ten times too big. Choice D,

9

, gives

9 \times 40 = 360

, which overshoots 320. A great strategy for these problems: whenever you see a missing factor, rewrite the equation as division. "Something times 40 equals 320" becomes "320 divided by 40." Then use the zero-drop trick with your basic multiplication facts. Knowing your times tables through

10 \times 10

makes these problems fast and easy — because

8 \times 4 = 32

is really the heart of this whole question.

Question 9

A school ordered 7 boxes of markers. Each box has 40 markers. Then the school gave away 50 markers. How many markers does the school have left?

$230$ (correct answer)
$280$
$330$
$240$

Explanation: This is a two-step word problem, and the key to solving these is doing the operations in the right order. When you see "ordered... then gave away," you need to first find the total amount before you can subtract what was given away. Start by finding how many markers the school got in all. With 7 boxes of 40 markers each, multiply:

7 \times 40 = 280

markers. Then subtract the 50 markers that were given away:

280 - 50 = 230

markers. That matches choice A. Choice B (

280

) is a trap — it's the total number of markers before giving any away. If you stopped after multiplying and forgot the subtraction step, you'd land here. Choice C (

330

) comes from adding 50 instead of subtracting:

280 + 50 = 330

. "Gave away" means the school has fewer markers, so you must subtract. Choice D (

240

) comes from a subtraction slip-up, like doing

280 - 40

instead of

280 - 50

, or miscounting when subtracting. A helpful tip: underline or circle the important numbers and action words in a word problem. Words like "gave away," "lost," or "used" signal subtraction, while "each" or "per" often signals multiplication. Always ask yourself, "Did I finish all the steps?" before choosing your answer — the most common trap in multi-step problems is stopping too early.

Question 10

A librarian puts books on shelves. Each shelf holds 30 books. She fills 6 shelves completely and puts 15 more books on another shelf. How many books did she place in all?

$210$
$180$
$105$
$195$ (correct answer)

Explanation: Word problems like this one are really testing two skills: figuring out which operations to use, and then doing them in the right order. When you see "each shelf holds " and "fills shelves," that's a multiplication signal. When you see "and more," that's an addition signal. Start with the full shelves: 6 shelves with 30 books each gives you

6 \times 30 = 180

books. Then add the extra 15 books on the partial shelf:

180 + 15 = 195

. That matches D. Now look at the traps. Choice A (

210

) comes from multiplying

30 \times 7 = 210

, as if all 7 shelves were full — but the 7th shelf only had 15 books, not 30. Choice B (

180

) is what you get if you stop after the multiplication and forget to add the 15 extra books. Choice C (

105

) is a mix-up where someone might have added first (

30 + 15 = 45

) or used the wrong numbers entirely — it doesn't reflect the situation at all. A good strategy for multi-step word problems: underline each number and label what it represents before calculating. Here you'd mark "30 = books per full shelf," "6 = full shelves," and "15 = extra books." That way you won't accidentally treat the partial shelf like a full one, which is the most common trap on problems like this.

Question 11

Leo has 4 boxes with 90 crayons in each box. How many crayons does he have in total?

360 crayons (correct answer)
900 crayons
36 crayons
94 crayons

Explanation: Leo has 4 boxes with 90 crayons each, so the total is 4 times 90, which is 360 crayons. Choice B (900 crayons) comes from multiplying with an extra zero in the wrong place. Choice C (36 crayons) drops a zero from the correct total by mistake. Choice D (94 crayons) comes from adding 4 and 90 instead of multiplying.

Question 12

What is $4 \times 70$ ?

28
2800
280 (correct answer)
74

Explanation: 280 is correct because

4 \times 70 = 280

. 28 is incorrect; it's the product of 4 and 7 without accounting for the extra zero in 70. 2800 is incorrect because it has one too many zeros. 74 is incorrect; it doesn't represent multiplying 4 by 70.

Question 13

Use the pattern: If $4\times5=20$ , what is $4\times50$ ?

20
200 (correct answer)
40
2000

Explanation: Since 50 is 10 times 5, the product 4 times 50 is 10 times the product of 4 times 5, so 4 times 50 equals 200. Choice A, 20, repeats the original fact without scaling it up. Choice C, 40, only doubles the original product instead of multiplying it by 10. Choice D, 2000, scales the product by 100 instead of 10.

Question 14

Ava has 7 bags with 10 marbles in each bag. How many marbles does she have in total?

17 marbles
7 marbles
700 marbles
70 marbles (correct answer)

Explanation: 70 marbles is correct because

7 \times 10 = 70

. 17 marbles is incorrect; it comes from adding 7 and 10 instead of multiplying. 7 marbles is incorrect because it's just the number of bags, not the total marbles. 700 marbles is incorrect; it has an extra zero, far more than the actual product.

Question 15

A coach gives 6 players 40 points each. How many points total?

46 points
60 points
24 points
240 points (correct answer)

Explanation: This question tests multiplying one-digit numbers by multiples of 10 in the range 10-90 (CCSS.3.NBT.3), specifically using place value strategies and properties of operations. To multiply a digit by a multiple of 10, use the pattern: first multiply the digit by the unit digit, then multiply the result by 10. For example, 6×40: Think of 40 as 4 tens. Multiply 6×4=24, then multiply by 10 to get 240 (or think: 24 tens = 240). In this problem, a coach gives 6 players 40 points each. This represents the multiplication 6×40. Choice A is correct because 6×40=240 using the pattern (6×4=24, then ×10=240) or place value (6×4 tens = 24 tens = 240). This demonstrates understanding of multiplying by multiples of 10. Choice C is incorrect because it shows only 6×4=24 and forgot to multiply by 10. This error occurs when students don't complete the pattern. To help students multiply by multiples of 10: Connect to basic facts (if you know 6×4=24, then 6×40=240). Use place value language (6×40 = 6×4 tens = 24 tens = 240). Model with base-10 blocks (6 groups of 4 tens rods).

Question 16

Mia buys 6 packs of 30 stickers. How many stickers total?

60 stickers
1800 stickers
180 stickers (correct answer)
18 stickers

Explanation: 180 stickers is correct because 6 times 30 equals 180. 60 stickers is incorrect because it does not match multiplying 6 by 30. 1800 stickers is incorrect because it adds an extra zero, mistaking the place value. 18 stickers is incorrect because it comes from 6 times 3, ignoring the correct place value.

Question 17

Lena has 6 packs of 30 stickers. How many stickers does she have in total?

60 stickers
180 stickers (correct answer)
1800 stickers
18 stickers

Explanation: 6 packs of 30 stickers gives 6 times 30, which equals 180 stickers, so B is correct. Choice A (60) uses only part of the packs. Choice C (1800) adds an extra zero to the correct product. Choice D (18) confuses the number of packs with the total number of stickers.

Question 18

What is $8 \times 40$ ?

320 (correct answer)
80
3200
48

Explanation: 320 is correct because 8 times 40 equals 320. 80 is incorrect because it uses only one of the factors. 3200 is incorrect because it adds an extra zero, mistaking the place value. 48 is incorrect because it comes from adding 8 and 40 instead of multiplying them.

Question 19

Kai has 6 groups of 20 marbles. How many marbles in all?

12 marbles
60 marbles
120 marbles (correct answer)
26 marbles

Explanation: Multiplying 6 groups by 20 marbles each gives 6 times 20, which is 120 marbles. Choice A, 12 marbles, comes from multiplying 6 by 2 and dropping a zero. Choice B, 60 marbles, comes from multiplying 6 by 10 instead of 20. Choice D, 26 marbles, comes from adding 6 and 20 instead of multiplying.

Question 20

Use skip counting by 20s six times to find $6 \times 20$ .

12
60
120 (correct answer)
26

Explanation: Skip counting by 20 six times gives 20, 40, 60, 80, 100, 120, so 6 x 20 = 120, making Choice C correct. Choice A (12) drops a zero from the correct product. Choice B (60) stops after only three skips instead of six. Choice D (26) comes from adding 6 + 20 instead of multiplying.