Welcome to our FREE OST Math practice test for grade 3, with answer key and answer explanations. This practice test’s realistic format and high-quality practice questions can help your student succeed on the OST Math test. Not only does the test closely match what students will see on the real OST, but it also comes with detailed answer explanations.

For this practice test, we’ve selected 20 real questions from past exams for your student’s OST Practice test. Your student will have the chance to try out the most common OST Math questions. For every question, there is an in-depth explanation of how to solve the question and how to avoid mistakes next time.

Use our free OST Math practice tests and study resources (updated for 2020) to help your students ace the OST Math test! Make sure to follow some of the related links at the bottom of this post to get a better idea of what kind of mathematics questions students need to practice.

## The Absolute Best Book** to Ace the Grade 3 OST** **Math** Test

## 10 Sample **Grade 3 OST** Math Practice Questions

1- There are 6 numbers in the box below. Which of the following list shows only even numbers from the numbers in the box?

☐A. \(15, 29, 42\)

☐B. \(15, 29, 83\)

☐C. \(15, 30, 42\)

☐D. \(42, 18, 30\)

2- Noah packs 18 boxes with crayons. Each box holds 40 crayons. How many crayons Noah can pack into these boxes?

☐A. 480

☐B. 540

☐C. 680

☐D. 720

3- A cafeteria menu had spaghetti with meatballs for $10 and bean soup for $6. How much would it cost to buy three plates of spaghetti with meatballs and two bowls of bean soup? __________

4- Which number correctly completes the number sentence \(25 × 50 =\) ?

☐A. 225

☐B. 900

☐C. 1250

☐D. 2250

5- Michael has 745 marbles. What is this number rounded to the nearest ten? ____________

6- There are 60 minutes in an hour. How many minutes are in 6 hours?

☐A. 300 minutes

☐B. 320 minutes

☐C. 360 minutes

☐D. 400 minutes

7- Which number correctly completes the number sentence \(55 × 14 =\)?

☐A. 550

☐B. 660

☐C. 770

☐D. 990

8- Use the picture below to answer the question.

Which fraction shows the shaded part of this square?

☐A. \(\frac{88}{100}\)

☐B. \(\frac{88}{10}\)

☐C. \(\frac{8.8}{100}\)

☐D. \(\frac{8}{100}\)

9- What number makes this equation true?

\(12 × 8 = ⎕\)

☐A. 88

☐B. 96

☐C. 100

☐D. 108

10- Kayla has 109 red cards and 88 white cards. How many more red cards than white cards does Kayla have?

☐A. 17

☐B. 19

☐C. 21

☐D. 27

11- A number sentence is shown below.

\(3 × 7 \space ⎕ \space 6 = 126\)

What symbol goes into the box to make the number sentence true?

☐A. \(×\)

☐B. \(÷\)

☐C. \(+\)

☐D. \(-\)

12- Liam had 845 marbles. Then, he gave 455 of the cards to his friend Ethan. After that, Liam lost 116 cards.

Which equation can be used to find the number of cards Eve has now?

☐A. \(845 – 455 + 116 = \)

☐B. \(845 – 455 – 116 =\)

☐C. \(845 + 455 + 116 = \)

☐D. \(845 + 455 – 116 = \)

13- What is the value of “B” in the following equation?

\(33 + B + 8 = 66\)

☐A. 16

☐B. 18

☐C. 22

☐D. 25

14- Mason is 18 months now and he usually eats six meals a day. How many meals does he eat in a week?

☐A. 36

☐B. 40

☐C. 42

☐D. 48

15- Which of the following list shows only fractions that are equivalent to \(\frac{1}{3}\)?

☐A. \(\frac{3}{9},\frac{5}{15},\frac{24}{72}\)

☐B. \(\frac{6}{12},\frac{5}{15},\frac{9}{27}\)

☐C. \(\frac{3}{9},\frac{4}{15},\frac{6}{18}\)

☐D. \(\frac{3}{9},\frac{5}{10},\frac{8}{24}\)

16- What mixed number is shown by the shaded rectangles?

☐A. \(3\frac{1}{2}\)

☐B. \(4\frac{1}{2}\)

☐C. 3

☐D. 4

17- The perimeter of a square is 24 units. Each side of this square is the same length.

What is the length of one side of the square in units?

☐A. 4

☐B. 5

☐C. 6

☐D. 7

18- There are two different cards on the table.

There are 3 rows that have 13 red cards in each row.

There are 24 white cards.

How many cards are there on the table?

☐A. 59

☐B. 63

☐C. 68

☐D. 70

19- Which of the following comparison of fractions is true?

☐A. \(\frac{2}{5}=\frac{4}{10}\)

☐B. \(\frac{2}{5}> \frac{4}{10}\)

☐C.\(\frac{2}{5}< \frac{4}{10}\)

☐D. \(\frac{2}{5}< \frac{2}{10}\)

20- What is the value of \(A\) in the equation \(64 ÷ A = 8\)

☐A. 2

☐B. 4

☐C. 6

☐D. 8

## Best **Grade 3 OST** Math Prep Resource for 2020

## Answers:

1- **D**

Even numbers always end with a digit of \(0, 2, 4, 6\) or \(8\).

So numbers \(30, 42, 18\) are just even numbers.

2- **D**

\(18 × 40 = 720\)

3-** 42**

3spaghetti with meatballs cost: \(3 × $10 = $30\)

2bowls of bean soup cost: \(2 × $6 = $12\)

3spaghetti with meatballs \(+\) 2bowls of bean soup cost: \($30 + $ 12 = $42\)

4- **C**

\(25 × 50 = 1250\)

5- **750**

We round the number up to the nearest ten if the last digit in the number is 5, 6, 7, 8, or 9.

We round the number down to the nearest ten if the last digit in the number is 1, 2, 3, or 4.

If the last digit is 0, then we do not have to do any rounding, because it is already to the ten.

Therefore, rounded number of 745 to the nearest ten is 750.

6- **C**

\(1\) hour \(= 60\) minutes

\(6\) hours\( = 6 × 60\) minutes\(⇒ 6\) hours\( = 360\) minutes

7- **C**

\(55 × 14 = 770\)

8- **A**

The model for the fraction is divided into 100 equal parts. We shade 88 parts of these 100 parts that it’s equal to \(\frac{88}{100}\)

9- **B**

\(12 × 8 = 96\)

10- **C**

Subtract 109 red cards and 88 white cards. The answer is 21

11- **A**

\(3 × 7 \space ⎕ \space 6 = 126\)

\(21\space ⎕\space 6= 126 ⇒ 126=21×6\)

12- **B**

Liam gave 455 of his marbles to his friend that means his marbles decreased then he lost 116 of his marbles that means his marbles decreased again.

13- **D**

\(33 + B + 8 = 66 ⇒ 41+B =66 ⇒ B =66 – 41 =25\)

14- **C**

If he eats 6 meals in 1 day

So in a week (7 days) he eats \((7 × 6 = 42)\) meals.

15- **A**All these fractions; \(\frac{3}{9},\frac{5}{15},\frac{24}{72}\) after simplification are equivalent to \(\frac{1}{3}\).

16- **A**

This shape shows 3 complete shaded triangles and a half of a triangle that is equal to \(3\frac{1}{2}\)

17- **A**

Perimeter of square formula \(= 4 ×\) side \(⇒ 24 = 4 ×\) side \(⇒\) side \(= 6\)

18- **B**

3 rows that have 13 red cards in each row means: \(3 × 13 = 39\) red cards

And there are 24 white cards on table too, so in total there are \(39 + 24 = 63\) cards on table

19- **A**

Simplify \(\frac{4}{10}\) that’s equal to \(\frac{2}{5}\)

20- **D**

\(64 ÷ 8 = 8\)

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