$a=1000$  

$10\%\cdot 1000=\frac{1}{10}\cdot 1000=100$  

$50\%\cdot 1000=\frac{1}{2}\cdot 1000=500$  

$20\%\cdot 1000=\frac{1}{5}\cdot 1000=200$  

$1\%\cdot 1000=\frac{1}{100}\cdot 1000=10$  

$25\%\cdot 1000=\frac{1}{4}\cdot 1000=250$  
$\underline{}$  

$a=40$  

$10\%\cdot 40=\frac{1}{10}\cdot 40=4$  

$50\%\cdot 40=\frac{1}{2}\cdot 40=20$  

$20\%\cdot 40=\frac{1}{5}\cdot 40=8$  

$1\%\cdot 40=\frac{1}{100}\cdot 40=0,4$  

$25\%\cdot 40=\frac{1}{4}\cdot 40=10$  
$\underline{}$  

$a=20000$  

$10\%\cdot 20000=\frac{1}{10}\cdot 20000=2000$  

$50\%\cdot 20000=\frac{1}{2}\cdot 20000=10000$   

$20\%\cdot 20000=\frac{1}{5}\cdot 20000=4000$  

$1\%\cdot 20000=\frac{1}{100}\cdot 20000=200$  

$25\%\cdot 20000=\frac{1}{4}\cdot 20000=5000$  
$\underline{}$  

$a=0,8$  

$10\%\cdot 0,8=\frac{1}{10}\cdot 0,8=0,08$  

$50\%\cdot 0,8=\frac{1}{2}\cdot 0,8=0,4$  

$20\%\cdot 0,8=\frac{1}{5}\cdot 0,8=\frac{1}{5}\cdot \frac{8}{10}=\frac{1}{5}\cdot \frac{4}{5}=\frac{4}{25}=\frac{16}{100}=0,16$  

$1\%\cdot 0,8=\frac{1}{100}\cdot 0,8=0,008$  

$25\%\cdot 0,8=\frac{1}{4}\cdot 0,8=0,2$  
$\underline{}$  

$a=1,2$  

$10\%\cdot 1,2=\frac{1}{10}\cdot 1,2=0,12$  

$50\%\cdot 1,2=\frac{1}{2}\cdot 1,2=0,6$  

$20\%\cdot 1,2=\frac{1}{5}\cdot 1,2=\frac{1}{5}\cdot 1\frac{1}{5}=\frac{1}{5}\cdot \frac{6}{5}=\frac{6}{25}=\frac{24}{100}=0,24$  

$1\%\cdot 1,2=\frac{1}{100}\cdot 1,2=0,012$  

$25\%\cdot 1,2=\frac{1}{4}\cdot 1,2=0,3$  
$\underline{}$  

$a=\frac{1}{4}$  

$10\%\cdot \frac{1}{4}=\frac{1}{10}\cdot \frac{1}{4}=\frac{1}{40}$  

$50\%\cdot \frac{1}{4}=\frac{1}{2}\cdot \frac{1}{4}=\frac{1}{8}$  

$20\%\cdot \frac{1}{4}=\frac{1}{5}\cdot \frac{1}{4}=\frac{1}{20}$  

$1\%\cdot \frac{1}{4}=\frac{1}{100}\cdot \frac{1}{4}=\frac{1}{400}$  

$25\%\cdot \frac{1}{4}=\frac{1}{4}\cdot \frac{1}{4}=\frac{1}{16}$  
$\underline{}$  

$a=\frac{2}{5}$  

$10\%\cdot \frac{2}{5}=\frac{1}{{\sout{10}}^5}\cdot \frac{{\sout{2}}^1}{5}=\frac{1}{25}$  

$50\%\cdot \frac{2}{5}=\frac{1}{{\sout{2}}^1}\cdot \frac{{\sout{2}}^1}{5}=\frac{1}{5}$  

$20\%\cdot \frac{2}{5}=\frac{1}{5}\cdot \frac{2}{5}=\frac{2}{25}$  

$1\%\cdot \frac{2}{5}=\frac{1}{{\sout{100}}^{50}}\cdot \frac{{\sout{2}}^1}{5}=\frac{1}{250}$  

$25\%\cdot \frac{2}{5}=\frac{1}{{\sout{4}}^2}\cdot \frac{{\sout{2}}^1}{5}=\frac{1}{10}$            

 

 

Liczba a	1000	40	20 000	0,8	1,2	1/4	2/5
10%	$100$	$4$	$2000$	$0,08$	$0,12$	$\frac{1}{40}$	$\frac{1}{25}$
50%	$500$	$20$	$10000$	$0,4$	$0,6$	$\frac{1}{8}$	$\frac{1}{5}$
20%	$200$	$8$	$4000$	$0,16$	$0,24$	$\frac{1}{20}$	$\frac{2}{25}$
1%	$10$	$0,4$	$200$	$0,008$	$0,012$	$\frac{1}{400}$	$\frac{1}{250}$
25%	$250$	$10$	$5000$	$0,2$	$0,3$	$\frac{1}{16}$	$\frac{1}{10}$