$\underset{50}{\underbrace{L}}\underset{20}{\underbrace{XX}}\underset{8}{\underbrace{VIII}}=50+20+8=78$  

 

$\underset{500}{\underbrace{D}}\underset{300}{\underbrace{\text{CCC}}}\underset{10}{\underbrace{X}}\underset{1}{\underbrace{I}}=500+300+10+1=811$  

 

$\underset{3000}{\underbrace{\text{MMM}}}\underset{100}{\underbrace{C}}\underset{60}{\underbrace{LX}}\underset{9}{\underbrace{IX}}=3000+100+60+9=3169$  

 

$\underset{300}{\underbrace{\text{CCC}}}\underset{50}{\underbrace{L}}\underset{30}{\underbrace{\text{XXX}}}\underset{6}{\underbrace{VI}}=300+50+30+6=386$  

 

$\underset{100}{\underbrace{C}}\underset{90}{\underbrace{XC}}\underset{9}{\underbrace{IX}}=100+90+9=199$  

 

$\underset{500}{\underbrace{D}}\underset{300}{\underbrace{\text{CCC}}}\underset{90}{\underbrace{XC}}\underset{8}{\underbrace{VIII}}=500+300+90+8=898$   

 

$\underset{500}{\underbrace{D}}\underset{100}{\underbrace{C}}\underset{2}{\underbrace{II}}=500+100+2=602$          

 

$\underset{2000}{\underbrace{\text{MM}}}\underset{300}{\underbrace{\text{CCC}}}\underset{10}{\underbrace{X}}\underset{4}{\underbrace{IV}}=2000+300+10+4=2314$  

 

$\underset{100}{\underbrace{C}}\underset{50}{\underbrace{L}}\underset{30}{\underbrace{\text{XXX}}}\underset{6}{\underbrace{VI}}=100+50+30+6=186$  

 

$\underset{90}{\underbrace{XC}}\underset{1}{\underbrace{I}}=90+1=91$