a) 25, 7 + 9, 48 + 14, 3
= ( 25, 7 + 14, 3 ) + 9, 48
= 40 + 9, 48
= 49, 48
b) 8, 24 + 3, 69 + 2, 31
= 8, 24 + ( 3, 69 + 2, 31 )
= 8, 24 + 6
= 14, 24
c) 8, 65 + 7, 6 + 1, 35 + 0, 4
= ( 8, 65 + 1, 35 ) + ( 7, 6 + 0, 4 )
= 10 + 8
= 18
d) 5, 92 + 0, 44 + 5, 56 + 4, 08
= ( 5, 92 + 4, 08 ) + ( 0, 44 + 5, 56 )
= 10 + 6
= 16
a 25,7+9,48+14,3
=40+9,48=49,48
b 8,24+3,69+2,31
6+8,2=14,2
c 8,65+7,6+1,35+0,4
10+8+1=19
d 5,92+0,44+5,56+4,08
=10+6=16
a) 25,7 + 9,48 + 14,3
= ( 25,7 + 14,3 ) + 9,48
= 40 + 9,48
= 49,48
b) 8,24 + 3,69 + 2,31
= 8,24 + ( 3,69 + 2,31 )
= 8,24 + 6
= 14,24
c) 8,65 + 7,6 + 1 + 1,35 + 0,4
= ( 8,65 + 1,35 ) + ( 7,6 + 0,4 ) + 1
= 10 + 8 + 1
= 19
d) 5,92 + 0,44 + 5,56 + 4,08
= ( 5,92 + 4,08 ) + ( 0,44 + 5,56 )
= 10 + 6
= 16
Bài 1.Tính nhanh:
a 25,7+9,48+14,3=(25,7 + 14,3) + 9.48
=40 + 9.48
=49.48
b 8,24+3,69+2,31=8,24+(3.69+2,31)
=8,24+6
=14.24
c)8,65+ 7,6+1,35+0,4=(8,65+1.35) + (7.6+0.4)
= 10+8
= 18
d 5,92+0,44+5,56+4.08=(5.92+4.08)+(0.44+5.56)
= 10+6
=16