This document is a lesson on calculating the areas of different shapes. It provides 5 practice problems to calculate the areas of various geometric figures using their measurements. The areas given are: 27mm2 for a 9mm by 3mm rectangle, 64dm2 for an 8dm by 8dm square, 30m2 for a 5m by 12m rectangle, 21cm2 for a 7cm by 6cm rectangle, and 18dam2 for a 6dam by 6dam square.

1. Calcul mentalCalcul mental
« Les aires »« Les aires »
Séquence n°5Séquence n°5

2. Calculer l'aire de
chaque figure.

3. n°1n°1

4. n°2n°2

5. n°3n°3

6. n°4n°4

7. n°5n°5

8. CorrectionCorrection

9. n°1n°1

10. n°1n°1
Aire = 9mm×3mm

11. n°1n°1
Aire = 9mm×3mm = 27mm
2

12. n°2n°2

13. n°2n°2
Aire = 8dm×8dm

14. n°2n°2
Aire = 8dm×8dm = 64dm
2

15. n°3n°3

16. n°3n°3
Aire =
5m×12m
2

17. n°3n°3
Aire =
5m×12m
2
=
60m2
2

18. n°3n°3
Aire =
5m×12m
2
=
60m2
2
= 30m2

19. n°3n°3
Aire =
5m×12m
2
=
60m2
2
= 30m2
Aire = 5m×
12m
2

20. n°3n°3
Aire =
5m×12m
2
=
60m2
2
= 30m2
Aire = 5m×
12m
2
= 5m×6m

21. n°3n°3
Aire =
5m×12m
2
=
60m2
2
= 30m2
Aire = 5m×
12m
2
= 5m×6m = 30m
2

22. n°4n°4

23. n°4n°4
Aire =
7cm×6cm
2

24. n°4n°4
Aire =
7cm×6cm
2
=
42cm
2
2

25. n°4n°4
Aire =
7cm×6cm
2
=
42cm
2
2
= 21cm2

26. n°4n°4
Aire =
7cm×6cm
2
=
42cm
2
2
= 21cm2
Aire = 7cm×
6cm
2

27. n°4n°4
Aire =
7cm×6cm
2
=
42cm
2
2
= 21cm2
Aire = 7cm×
6cm
2
= 7cm×3cm

28. n°4n°4
Aire =
7cm×6cm
2
=
42cm
2
2
= 21cm2
Aire = 7cm×
6cm
2
= 7cm×3cm = 21cm
2

29. n°5n°5

30. n°5n°5
Aire =
6dam×6dam
2

31. n°5n°5
Aire =
6dam×6dam
2
=
36dam
2
2

32. n°5n°5
Aire =
6dam×6dam
2
=
36dam
2
2
= 18dam
2

33. n°5n°5
Aire =
6dam×6dam
2
=
36dam
2
2
= 18dam
2
Aire = 6dam×
6 dam
2

34. n°5n°5
Aire =
6dam×6dam
2
=
36dam
2
2
= 18dam
2
Aire = 6dam×
6 dam
2
= 6dam×3dam

35. n°5n°5
Aire =
6dam×6dam
2
=
36dam
2
2
= 18dam
2
Aire = 6dam×
6 dam
2
= 6dam×3dam = 18dam2