Avoid using \startformula \stopformula in itemize. Use \dfrac to get
display style fraction.


\defineenumeration
  [exercici]
  [alternative=serried, before={\blank[medium]\testpage[1]},
text={Exercici}, stopper={.\space}, width=fit, headstyle=\ss,
distance=0.25em, width=fit, headcolor=exercici_color, title=yes,
titlestyle=\ss, titledistance=0em, left={\bgroup\bf}, right={\egroup},
after={\blank[big]}, prefix=yes, prefixsegments=section, way=section]
\starttext

\section{Operacions amb fraccions}

\subject{Preguntes}

\startexercici[exercici:operacions-amb-fraccions-1]{suma i resta} Opereu:
\startitemize[a, columns, three]
\item\m{\dfrac{2}{7} + \dfrac{6}{7} - \dfrac{1}{7}}
\item\m{\dfrac{5}{8} + \dfrac{9}{8}}
\item\m{\dfrac{1}{4} + 5 - \dfrac{1}{4}}
\item\m{\dfrac{3}{5} - \dfrac{2}{5} + \dfrac{11}{5}}
\item\m{\dfrac{2}{3} + \dfrac{1}{4}}
\item\m{5 + \dfrac{4}{5}}
\item\m{\dfrac{2}{3} + \dfrac{5}{8} - \dfrac{1}{9}}
\item\m{10 - \dfrac{1}{6} + \dfrac{6}{8}}
\item\m{\dfrac{3}{10} + \dfrac{7}{12}}
\stopitemize
\stopexercici

\startexercici[exercici:operacions-amb-fraccions-2]{multiplicació i
divisió} Opereu:
\startitemize[a, columns, three]
\item\m{3 \cdot \dfrac{5}{3}}
\item\m{\dfrac{3}{4} \cdot \dfrac{2}{5}}
\item\m{\dfrac{1}{3} \cdot \dfrac{3}{4} \div \dfrac{1}{5}}
%\column
\item\m{5 \div \dfrac{7}{10} \cdot 7 \div \dfrac{2}{5}}
\item\m{\dfrac{1}{2} \cdot \dfrac{1}{2}}
\item\m{\dfrac{3}{2} \div \dfrac{2}{3} \div \dfrac{5}{4}}
%\column
\item\m{\dfrac{2}{3} \colon \dfrac{2}{5}}
\item\m{\dfrac{3}{4} \colon \dfrac{1}{2} \cdot 6}
\item\m{\dfrac{2}{3} \colon \dfrac{3}{4} \cdot \dfrac{1}{2}}
\stopitemize
\stopexercici

\startexercici[exercici:operacions-amb-fraccions-3]{operacions combinades}
\startitemize[a, columns, three]
\item\m{\dfrac{3}{4} + \dfrac{2}{5} \cdot \dfrac{1}{2}}
\item\m{\dfrac{2}{5} \div \dfrac{3}{5} - \dfrac{1}{4}}
\item\m{\left( 2 + \dfrac{3}{5} \right) \div \dfrac{4}{3}}
\item\m{\dfrac{2}{3} - \dfrac{5}{6}\cdot 8}
\item\m{4 + \dfrac{3}{5} - \left(2 - \dfrac{1}{2}\right)}
\item\m{4 \cdot \left(\dfrac{5}{6} - \dfrac{1}{4} + \dfrac{4}{9}\right)}
\item\m{\dfrac{5}{6} - \left(\dfrac{1}{5} + \dfrac{1}{3}\right)}
\item\m{\dfrac{5}{6} \div \left( \dfrac{2}{5} - \dfrac{1}{10}\right)}
\item\m{4 \cdot \dfrac{2}{3} \cdot \left(\dfrac{2}{4} \div
\dfrac{8}{10}\right)}
\item\m{\dfrac{3}{4} + \dfrac{1}{2} \cdot \dfrac{4}{10}}
\item\m{\dfrac{10}{12} - \left(\dfrac{1}{10} + \dfrac{3}{8}\right)}
\item\m{\left(\dfrac{1}{2} + 2\right) \cdot \left(2 - \dfrac{1}{4}\right)}
\item\m{\left(\dfrac{3}{4} + \dfrac{1}{4}\right) \div \left(\dfrac{5}{6} -
\dfrac{1}{3}\right)}
\item\m{5 + 10 - \dfrac{1}{10} + 25}
\item\m{\dfrac{1}{3} + \dfrac{1}{2} - \dfrac{2}{5}}
\item\m{\left(\dfrac{1}{2} + \dfrac{2}{10}\right) \cdot \dfrac{2}{6}}
\item\m{5 + \dfrac{1}{3} \cdot \dfrac{5}{3}}
\item\m{\left( 5 + \dfrac{1}{3} \right) \cdot \dfrac{5}{3}}
\stopitemize
\stopexercici
\stoptext


Xavier B. via ntg-context <ntg-context@ntg.nl> 於 2022年2月25日 週五 上午6:10寫道：

> Even if I change
> \startexercici[exercici:operacions-amb-fraccions-2]{multiplicació i
> divisió} Opereu:
> \startitemize[a, columns, three]
>
>
> for
>
> \startexercici[exercici:operacions-amb-fraccions-2]{multiplicació i
> divisió} Opereu:
> \startitemize[a, columns]
>
>
> the 'c' jumps.
>
> Isn't ConTeXt capable of handle that?
>
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