①600﹣300÷20×5
②(4.8﹣3.8÷2)×0.3
③3.45×99×2+6.9
④(8+ )÷4
⑤ ÷9+ ×
⑥ ÷[ ×( - )]
①836-192÷8×16
②1.4÷(1.4+0.7)
③0.8×0.4×12.5×0.25
④ ÷6+ ÷20
⑤14×19×( + )
⑥ ÷[( + )÷ ]