1.四年级上册数学第三单元试题名类分值1。“巧算”又对又快:35分【10+16+9】直接写数字:①30×12 =②23×4 =③540-310 =④4×140 =⑤630+70 =⑤130×20 =⑦180×5 =⑧170×5 =⑨500×5 =⑩212。垂直计算:（1）236×43 =（2）208×56 =（3）720×42 =（4）480×50 = 3，估计下列问题:（1）89×202 ≈≈≈≈≈≈≈≈≈≈≈≈≈≈≈≈≈