Grade 5 Math Test Worksheet featuring problems on number composition, missing numbers, rounding, and fraction to decimal conversion.

Let's solve the problems step by step.

---

Problem 1: Write the 5-digit numbers

We need to add the given numbers and write the results as 5-digit numbers.

#### 1.1. \( 30,000 + 100 + 4 \)
\[
30,000 + 100 + 4 = 30,104
\]

#### 1.2. \( 80,000 + 4,000 + 70 + 3 \)
\[
80,000 + 4,000 + 70 + 3 = 84,073
\]

#### 1.3. \( 40,000 + 5,000 + 700 + 70 + 6 \)
\[
40,000 + 5,000 + 700 + 70 + 6 = 45,776
\]

#### 1.4. \( 90,000 + 8,000 + 600 + 60 + 5 \)
\[
90,000 + 8,000 + 600 + 60 + 5 = 98,665
\]

#### 1.5. \( 60,000 + 1,000 + 600 + 10 + 1 \)
\[
60,000 + 1,000 + 600 + 10 + 1 = 61,611
\]

Answers for Problem 1:
\[
\boxed{30104, 84073, 45776, 98665, 61611}
\]

---

Problem 2: Find the missing numbers

We need to determine the missing numbers in each equation.

#### 2.1. \( \_\_\_\_\_ + 90,000 + 600 + 900 + 8 = 99,638 \)
First, add the known numbers:
\[
90,000 + 600 + 900 + 8 = 91,508
\]
Now, subtract this sum from 99,638:
\[
99,638 - 91,508 = 8,130
\]
So, the missing number is:
\[
\boxed{8130}
\]

#### 2.2. \( \_\_\_\_\_ + 100 + 90 + 4,000 = 64,200 \)
First, add the known numbers:
\[
100 + 90 + 4,000 = 4,190
\]
Now, subtract this sum from 64,200:
\[
64,200 - 4,190 = 60,010
\]
So, the missing number is:
\[
\boxed{60010}
\]

#### 2.3. \( 50 + 50,000 + 400 + \_\_\_\_\_ + 3 = 56,423 \)
First, add the known numbers:
\[
50 + 50,000 + 400 + 3 = 50,453
\]
Now, subtract this sum from 56,423:
\[
56,423 - 50,453 = 5,970
\]
So, the missing number is:
\[
\boxed{5970}
\]

#### 2.4. \( 0 + \_\_\_\_\_ + 900 + 5,000 + \_\_\_\_\_ = 45,900 \)
Let the missing numbers be \( x \) and \( y \). The equation becomes:
\[
x + 900 + 5,000 + y = 45,900
\]
Combine the known numbers:
\[
x + y + 5,900 = 45,900
\]
Subtract 5,900 from both sides:
\[
x + y = 40,000
\]
Without additional constraints, there are infinitely many solutions. However, if we assume the problem intends for equal distribution (a common assumption in such problems), we can set \( x = y \):
\[
x = y = 20,000
\]
So, the missing numbers are:
\[
\boxed{20000, 20000}
\]

#### 2.5. \( 6 + 700 + \_\_\_\_\_ + 10,000 + 70 = 16,776 \)
First, add the known numbers:
\[
6 + 700 + 10,000 + 70 = 10,776
\]
Now, subtract this sum from 16,776:
\[
16,776 - 10,776 = 6,000
\]
So, the missing number is:
\[
\boxed{6000}
\]

Answers for Problem 2:
\[
\boxed{8130, 60010, 5970, 20000, 20000, 6000}
\]

---

Problem 3: Round to the accuracy of the underlined digit

We need to round each number to the accuracy of the underlined digit.

#### 3.1. \( 3,976 \) (underline on 3)
The digit 3 is in the thousands place. Since there are no digits to the right of it, the number remains:
\[
\boxed{4000}
\]

#### 3.2. \( 3,863 \) (underline on 8)
The digit 8 is in the hundreds place. The next digit (6) is 5 or greater, so we round up:
\[
\boxed{3900}
\]

#### 3.3. \( 73,036 \) (underline on 0)
The digit 0 is in the tens place. The next digit (3) is less than 5, so we do not round up:
\[
\boxed{73000}
\]

#### 3.4. \( 86,05 \) (underline on 6)
The digit 6 is in the tens place. The next digit (0) is less than 5, so we do not round up:
\[
\boxed{8600}
\]

#### 3.5. \( 98,428 \) (underline on 4)
The digit 4 is in the hundreds place. The next digit (2) is less than 5, so we do not round up:
\[
\boxed{98000}
\]

Answers for Problem 3:
\[
\boxed{4000, 3900, 73000, 8600, 98000}
\]

---

Problem 4: Convert to decimals

We need to convert the given mixed numbers to decimals.

#### 4.1. \( 58 \text{ and } \frac{5}{10} \)
\[
58 + \frac{5}{10} = 58 + 0.5 = 58.5
\]

#### 4.2. \( 14 \text{ and } \frac{2}{100} \)
\[
14 + \frac{2}{100} = 14 + 0.02 = 14.02
\]

#### 4.3. \( 2 \text{ and } \frac{4}{5} \)
\[
2 + \frac{4}{5} = 2 + 0.8 = 2.8
\]

#### 4.4. \( 1 \text{ and } \frac{2}{4} \)
\[
1 + \frac{2}{4} = 1 + 0.5 = 1.5
\]

#### 4.5. \( 3 \text{ and } \frac{9}{10} \)
\[
3 + \frac{9}{10} = 3 + 0.9 = 3.9
\]

Answers for Problem 4:
\[
\boxed{58.5, 14.02, 2.8, 1.5, 3.9}
\]

---

Final Answers:

\[
\boxed{30104, 84073, 45776, 98665, 61611, 8130, 60010, 5970, 20000, 20000, 6000, 4000, 3900, 73000, 8600, 98000, 58.5, 14.02, 2.8, 1.5, 3.9}
\]