Ressources Mathématiques

Automatismes 5e : Fractions

Additionner et soustraire des fractions, simplifier, comparer, fraction d'une quantité.

Cherche chaque réponse de tête (ou au brouillon) AVANT de regarder les propositions, sans calculatrice.

Calculer \(\dfrac{13}{15} - \dfrac{4}{2}\) (résultat irréductible). \(-\dfrac{17}{15}\) \(\dfrac{3}{10}\) \(\dfrac{17}{15}\) \(\dfrac{9}{17}\)	Calculer \(\dfrac{13}{8} + \dfrac{8}{12}\) (résultat irréductible). \(-\dfrac{55}{24}\) \(\dfrac{21}{20}\) \(\dfrac{7}{32}\) \(\dfrac{55}{24}\)
Quelle comparaison est juste ? \(\dfrac{5}{4} = \dfrac{8}{6}\) \(\dfrac{8}{6} \lt \dfrac{5}{4}\) \(\dfrac{5}{4} \lt \dfrac{8}{6}\) \(\dfrac{5}{4} \gt \dfrac{8}{6}\)	Calculer \(\dfrac{6}{7} + \dfrac{1}{5}\) (résultat irréductible). \(\dfrac{7}{12}\) \(\dfrac{37}{35}\) \(\dfrac{1}{5}\) \(-\dfrac{37}{35}\)
Quelle comparaison est juste ? \(\dfrac{7}{4} = \dfrac{8}{7}\) \(\dfrac{8}{7} \gt \dfrac{7}{4}\) \(\dfrac{7}{4} \lt \dfrac{8}{7}\) \(\dfrac{7}{4} \gt \dfrac{8}{7}\)	Combien font \(\dfrac{3}{9}\) de 90 ? \(30\) \(87\) \(10\) \(270\)
Calculer \(\dfrac{11}{8} + \dfrac{10}{5}\) (résultat irréductible). \(\dfrac{27}{8}\) \(-\dfrac{27}{8}\) \(\dfrac{21}{40}\) \(\dfrac{21}{13}\)	Quelle comparaison est juste ? \(\dfrac{5}{3} \lt \dfrac{3}{5}\) \(\dfrac{3}{5} \gt \dfrac{5}{3}\) \(\dfrac{5}{3} \gt \dfrac{3}{5}\) \(\dfrac{5}{3} = \dfrac{3}{5}\)
Calculer \(\dfrac{2}{11} + \dfrac{6}{2}\) (résultat irréductible). \(\dfrac{8}{13}\) \(\dfrac{4}{11}\) \(-\dfrac{35}{11}\) \(\dfrac{35}{11}\)	Calculer \(\dfrac{9}{10} + \dfrac{10}{3}\) (résultat irréductible). \(-\dfrac{127}{30}\) \(\dfrac{19}{13}\) \(\dfrac{127}{30}\) \(\dfrac{19}{30}\)