Question

[Pham Trong Bach]

Tính nhẩm:

a) 15 cm2 + 20 cm2 = ..................

60 cm2 - 42 cm2 = ..................

20 cm2 + 10 cm2 + 15 cm2 = ..................

b) 12 cm2 x 2 = ..................

40 cm2 : 4 = ..................

50 cm2 - 40 cm2 + 10 cm2 = ..................

Answer 1

[Cao Minh Tâm]

a) 15 cm2 + 20 cm2 = 35 cm2

60 cm2 - 42 cm2 = 18 cm2

20 cm2 + 10 cm2 + 15 cm2 = 45 cm2

b) 12 cm2 x 2 = 24 cm2

40 cm2 : 4 = 10 cm2

50 cm2 - 40 cm2 + 10 cm2 = 20 cm2