Convert the following Hindu-Arabic numerals to Roman numerals: 38, 221, 1000, 110, 175, 836.

$$30 = \text{XXX}$$ $$8 = \text{VIII}$$

$$38 = \text{XXXVIII}$$

The Roman numeral for 38 is $\boxed{\text{XXXVIII}}$.

2) 221

$$200 = \text{CC}$$ $$20 = \text{XX}$$ $$1 = \text{I}$$

$$221 = \text{CCXXI}$$

The Roman numeral for 221 is $\boxed{\text{CCXXI}}$.

3) 1,000

$$1000 = \text{M}$$

The Roman numeral for 1,000 is $\boxed{\text{M}}$.

4) 110

$$100 = \text{C}$$ $$10 = \text{X}$$

$$110 = \text{CX}$$

The Roman numeral for 110 is $\boxed{\text{CX}}$.

5) 175

$$100 = \text{C}$$ $$70 = \text{LXX}$$ $$5 = \text{V}$$

$$175 = \text{CLXXV}$$

The Roman numeral for 175 is $\boxed{\text{CLXXV}}$.

6) 836

$$800 = \text{DCCC}$$ $$30 = \text{XXX}$$ $$6 = \text{VI}$$

$$836 = \text{DCCCXXXVI}$$

The Roman numeral for 836 is $\boxed{\text{DCCCXXXVI}}$.

7) 99

$$90 = \text{XC} \quad (100 - 10)$$ $$9 = \text{IX} \quad (10 - 1)$$

$$99 = \text{XCIX}$$

The Roman numeral for 99 is $\boxed{\text{XCIX}}$.

8) 217

$$200 = \text{CC}$$ $$10 = \text{X}$$ $$7 = \text{VII}$$

$$217 = \text{CCXVII}$$

The Roman numeral for 217 is $\boxed{\text{CCXVII}}$.

9) 590

$$500 = \text{D}$$ $$90 = \text{XC} \quad (100 - 10)$$

$$590 = \text{DXC}$$

The Roman numeral for 590 is $\boxed{\text{DXC}}$.

10) 384

$$300 = \text{CCC}$$ $$80 = \text{LXXX}$$ $$4 = \text{IV} \quad (5 - 1)$$

$$384 = \text{CCCLXXXIV}$$

The Roman numeral for 384 is $\boxed{\text{CCCLXXXIV}}$.