$a)$  

$18+52=70$  

$101-47=54$  

$27\cdot 3=81$  

$4\cdot 125=500$  

$270:30=9$  

$488:4=122$  

 

$b)$  

$2,7\cdot 10=27$  

$100\cdot 8,54=854$  

$27,3:10=2,73$  

$16,2:100=0,162$  

$5,4:100=0,054$  

 

$c)$  

$4,7+5,4=10,1$  

$5,5-1,8=3,7$  

$4\cdot 1,05=4,2$  

$6,2:0,2=31$  

$20\cdot 7,5=150$  

$2,5\cdot 400=1000$  

 

$d)$  

$\frac{1}{3}+1\frac{1}{6}=\frac{1^{\cdot 2}}{3_{\cdot 2}}+1\frac{1}{6}=\frac{2}{6}+1\frac{1}{6}=1\frac{3}{6}=1\frac{3^{:3}}{6_{:3}}=1\frac{1}{2}$  

$5\frac{1}{4}-2\frac{3}{4}=4\frac{4+1}{4}-2\frac{3}{4}=4\frac{5}{4}-2\frac{3}{4}=2\frac{2}{4}=2\frac{1}{2}$  

$\frac{1}{2}+0,75=0,5+0,75=1,25$  

${\left(\frac{1}{2}\right)}^3=\frac{1^3}{2^3}=\frac{1}{8}$  

$\frac{2}{5}\cdot \frac{1}{3}=\frac{2\cdot 1}{5\cdot 3}=\frac{2}{15}$  

$1\frac{1}{2}\cdot \frac{1}{2}=\frac{3}{2}\cdot \frac{1}{2}=\frac{3\cdot 1}{2\cdot 2}=\frac{3}{4}$  

$1\frac{1}{2}:\frac{1}{2}=\frac{3}{2}:\frac{1}{2}=\frac{3}{\sout{2}}\cdot \frac{\sout{2}}{1}=3$