Question

6.4-3.2×1.8÷6.1简便计算

（2014•广州模拟）计算下列各题，能简便的请用简便方法 （1） 4 7 ×23 12 13 + 4 7 × 1 13 +16× 1 7 （2）41.2×3.6+16×1 1 4 +53.7×6.4 （3）0.78÷2.6×1.8÷0.12 （4）12.6×125%+3 2 5 ÷ 4 5 ．

Answer 1

（1） 4 7 ×23 12 13 + 4 7 × 1 13 +16× 1 7 = 4 7 ×（23 12 13 + 1 13 ）+4×4× 1 7 = 4 7 ×24+4× 4 7 = 4 7 ×（24+4） = 4 7 ×28 =16； （2）41.2×3.6+16×1 1 4 +53.7×6.4 =41.2×3.6+20+53.7×6.4 =41.2×（10-6.4）+20+53.7×6.4 =41.2×10-41.2×6.4+20+53.7×6.4 =412+20+53.7×6.4-41.2×6.4 =432+（53.7-41.2）×6.4 =432+12.5×8×0.8 =432+80 =512； （3）0.78÷2.6×1.8÷0.12 =（0.78÷2.6）×（1.8÷0.12） =0.3×15 =4.5； （4）12.6×125%+3 2 5 ÷ 4 5 =12.6×1.25+3 2 5 ×1.25 =（12.6+3 2 5 ）×1.25 =16×1.25 =1×（8×1.25） =20．