(1)6.25÷0.25×0.6 =25×0.6, =15; (2)68.04÷(0.21×3.6) =68.04÷0.21÷3.6, =324÷3.6, =90; (3)2.02×(1.027÷0.26) =2.02×3.95, =7.979; (4)12.8-10.8÷4.5 =12.8-2.4, =10.4; (5)2.7÷0.75+76.4 =3.6+76.4, =80; (6)0.486+0.01+3.99 =0.486+(0.01+3.99), =0.486+4, =4.486; (7)1.25×11×4×0.8 =1.25×0.8×4×11, =1×4×11, =4×11, =44; (8)19.75-6.45-3.55 =19.75-(6.45+3.55), =19.75-10, =9.75; (9)90÷25÷4 =90÷(25×4), =90÷100, =0.9; (10)5.6÷2.4 =5.6÷(0.8×3), =5.6÷0.8÷3, =7÷3, ≈2.33. |