×4= ×= += ××4= 2﹣1.2=3.5+5.8= ×= 3×1= 4÷0.5= 296﹣63=﹣= 10﹣9.9= 8.2×10= 0×= ×36=1﹣= += ﹣= 0.6×10= 4××4=
300﹣250÷25.
请脱式计算. 200+25×33 (25+26)×48.
①122﹣36+64 =122﹣(36+64) =122﹣100 =22订正:① ②99×25 =(100﹣1)×25 =100﹣1×25 =75订正:② ③720÷(8×3) =720÷8×3 =90×3 =270订正:③
递等式计算: 603﹣105÷5(842﹣356)×7 503+198÷2 8×(755÷5)
口算. 27÷3×3= 43×200= 75×500=75×9÷9×75= 85﹣85÷5= 65×99=