①772-317+128-283
②2.4÷( -20%)
③1-
④5.125× +2.875÷4
⑤
2÷24= ×= 16×40%=
112= 51×99≈ 3.5×2÷3.5×5=
1.2×0.3= ﹣= 32÷53×0=
0.25÷= 1﹣0.09= +20%=
①42×()
②7.5×(26-10)+9.7
③0.8×4×12.5×2.5
④÷[1-(+0.25) ]
①99.7×13+ ×13
②12.78﹣(1.17+2.78)﹣3.83
③910÷1.3×0.7
④67× ﹣9÷1.25+ ×2
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