1)
[tex] \frac{5}{21} \div \frac{10}{7} [/tex]
[tex] \frac{5}{21} \times \frac{7}{10} [/tex]
[tex] \frac{1}{3} \times \frac{1}{2} [/tex]
[tex] \frac{1}{6} [/tex]
2)
[tex]( \frac{1}{3} - \frac{1}{9}) \times 27[/tex]
[tex] \frac{2}{9} \times 27[/tex]
[tex]2 \times 3[/tex]
[tex]6[/tex]
3)
[tex] \frac{4}{9} \div ( \frac{1}{3} \times \frac{5}{3} ) [/tex]
[tex] \frac{4}{9} \div \frac{5}{9} [/tex]
[tex] \frac{4}{9} \times \frac{9}{5} [/tex]
[tex]4 \times \frac{1}{5} [/tex]
[tex] \frac{4}{5} [/tex]
4)
[tex] \frac{2}{5} + \frac{4}{9} \div \frac{10}{9} [/tex]
[tex] \frac{2}{5} + \frac{4}{9} \times \frac{9}{10} [/tex]
[tex] \frac{2}{5} + 2 \times \frac{1}{5} [/tex]
[tex] \frac{2}{5} + \frac{5}{2} [/tex]
[tex] \frac{4}{5} [/tex]
6)
[tex] \frac{2}{3}36[/tex]
[tex]2 \times 12[/tex]
[tex]24 \: \: \: lei[/tex]
7)
[tex] \frac{35}{100} \times 700 kg[/tex]
[tex]35 \times 7kg[/tex]
[tex]245 \: kg[/tex]
