(1)1.29+3.7+0.71+6.3, =(1.29+0.71)+(3.7+6.3), =2+10, =12; (2)23.4-8.54-1.46, =23.4-(8.54+1.46), =23.4-10, =13.4; (3)6.75×0.5+4.86, =3.375+4.86, =8.235; (4)19×3.6-3.6×9, =3.6×(19-9), =3.6×10, =36; (5)2.5×1.8×0.04, =2.5×0.04×1.8, =0.1×1.8, =0.18; (6)10.24÷1.25÷8, =10.24÷(1.25×8), =10.24÷10, =1.024. |