Math test for Grade 3 (A+B) featuring multiplication exercises and problem-solving tasks.

Let's solve the problems step by step.

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Problem 1: Fill in the blanks with the convenient number

We need to calculate the products of the given multiplication expressions.

#### Calculations:
1. \( 5 \times 9 = 45 \)
2. \( 6 \times 4 = 24 \)
3. \( 4 \times 8 = 32 \)
4. \( 3 \times 7 = 21 \)
5. \( 1 \times 8 = 8 \)
6. \( 5 \times 5 = 25 \)

#### Answer:
\[
\begin{aligned}
&5 \times 9 = 45 \\
&6 \times 4 = 24 \\
&4 \times 8 = 32 \\
&3 \times 7 = 21 \\
&1 \times 8 = 8 \\
&5 \times 5 = 25
\end{aligned}
\]

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Problem 2: In each star, underline the largest product

We need to compare the two products in each star and underline the larger one.

#### Star 1:
- \( 3 \times 2 = 6 \)
- \( 4 \times 5 = 20 \)
The larger product is \( 20 \).

#### Star 2:
- \( 4 \times 8 = 32 \)
- \( 3 \times 9 = 27 \)
The larger product is \( 32 \).

#### Star 3:
- \( 3 \times 0 = 0 \)
- \( 1 \times 10 = 10 \)
The larger product is \( 10 \).

#### Star 4:
- \( 5 \times 7 = 35 \)
- \( 4 \times 6 = 24 \)
The larger product is \( 35 \).

#### Answer:
Underline the following:
- Star 1: \( 4 \times 5 \)
- Star 2: \( 4 \times 8 \)
- Star 3: \( 1 \times 10 \)
- Star 4: \( 5 \times 7 \)

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Problem 3: Write each multiplication sentence as a repeated addition sentence

We need to express each multiplication as repeated addition.

#### A) \( 5 \times 3 \):
\[ 5 \times 3 = 5 + 5 + 5 = 15 \]

#### B) \( 2 \times 6 \):
\[ 2 \times 6 = 6 + 6 = 12 \]

#### C) \( 4 \times 7 \):
\[ 4 \times 7 = 7 + 7 + 7 + 7 = 28 \]

#### D) \( 3 \times 8 \):
\[ 3 \times 8 = 8 + 8 + 8 = 24 \]

#### Answer:
\[
\begin{aligned}
&\text{A) } 5 \times 3 = 5 + 5 + 5 = 15 \\
&\text{B) } 2 \times 6 = 6 + 6 = 12 \\
&\text{C) } 4 \times 7 = 7 + 7 + 7 + 7 = 28 \\
&\text{D) } 3 \times 8 = 8 + 8 + 8 = 24
\end{aligned}
\]

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Problem 4: Use the appropriate sign >, <, or =

We need to compare the products of the given expressions.

#### A) \( 2 \times 5 \) vs \( 1 \times 10 \):
- \( 2 \times 5 = 10 \)
- \( 1 \times 10 = 10 \)
So, \( 2 \times 5 = 1 \times 10 \).

#### B) \( 3 \times 5 \) vs \( 2 \times 3 \):
- \( 3 \times 5 = 15 \)
- \( 2 \times 3 = 6 \)
So, \( 3 \times 5 > 2 \times 3 \).

#### C) \( 2 \times 9 \) vs \( 5 \times 6 \):
- \( 2 \times 9 = 18 \)
- \( 5 \times 6 = 30 \)
So, \( 2 \times 9 < 5 \times 6 \).

#### D) \( 4 \times 4 \) vs \( 3 \times 3 \):
- \( 4 \times 4 = 16 \)
- \( 3 \times 3 = 9 \)
So, \( 4 \times 4 > 3 \times 3 \).

#### Answer:
\[
\begin{aligned}
&2 \times 5 = 1 \times 10 \\
&3 \times 5 > 2 \times 3 \\
&2 \times 9 < 5 \times 6 \\
&4 \times 4 > 3 \times 3
\end{aligned}
\]

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Problem 5: Find the product, and then arrange in increasing order

We need to calculate the products and then arrange them in increasing order.

#### Calculations:
1. \( 5 \times 8 = 40 \)
2. \( 4 \times 2 = 8 \)
3. \( 5 \times 11 = 55 \)
4. \( 4 \times 12 = 48 \)

#### Products:
- \( 5 \times 8 = 40 \)
- \( 4 \times 2 = 8 \)
- \( 5 \times 11 = 55 \)
- \( 4 \times 12 = 48 \)

#### Arranging in increasing order:
\[ 8 < 40 < 48 < 55 \]

#### Answer:
\[
\boxed{8 < 40 < 48 < 55}
\]

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Final Answers:

1. \[
\begin{aligned}
&5 \times 9 = 45 \\
&6 \times 4 = 24 \\
&4 \times 8 = 32 \\
&3 \times 7 = 21 \\
&1 \times 8 = 8 \\
&5 \times 5 = 25
\end{aligned}
\]
2. Underline:
- Star 1: \( 4 \times 5 \)
- Star 2: \( 4 \times 8 \)
- Star 3: \( 1 \times 10 \)
- Star 4: \( 5 \times 7 \)
3. \[
\begin{aligned}
&\text{A) } 5 \times 3 = 5 + 5 + 5 = 15 \\
&\text{B) } 2 \times 6 = 6 + 6 = 12 \\
&\text{C) } 4 \times 7 = 7 + 7 + 7 + 7 = 28 \\
&\text{D) } 3 \times 8 = 8 + 8 + 8 = 24
\end{aligned}
\]
4. \[
\begin{aligned}
&2 \times 5 = 1 \times 10 \\
&3 \times 5 > 2 \times 3 \\
&2 \times 9 < 5 \times 6 \\
&4 \times 4 > 3 \times 3
\end{aligned}
\]
5. \[
\boxed{8 < 40 < 48 < 55}
\]