0.45 × 4 ＝ 1.8 0.75 × 4.3 ＝ 3.225 1.05 × 4.6 ＝ 4.83 1.35 × 4.9 ＝ 6.615 1.65 × 5.2 ＝ 8.58 1.95 × 5.5 ＝ 10.725 2.25 × 5.8 ...有没有分数乘分数的？1/2 ×7/8 =7/162/3 ×5/12=5/181/3 ×9/10=3/102/3 ×2/5 =4/151/4 ×4/7 =1/7 3/4 × 26/35= 39/701/5 × 32/35= 17/932/5 ×2/7 =4/353/5 ×1/3 =1/5 4/5 ×8/21= 25/821/6 ×3/7 =1/145/6 × 10/21= 25/631/7 × 11/21=3/402/7 ×4/7 =8/493/7 × 13/21= 13/494/7 ×2/3 =8/215/7 ×5/7 = 25/496/7 × 16/21= 32/491/8 × 17/21=8/793/8 ×6/7 =9/285/8 × 19/21= 13/237/8 × 20/21=5/6 1/9 ×5/8 =5/722/9 ×5/9 = 10/814/9 × 35/72=8/375/9 ×5/12=3/137/9 × 25/72= 10/378/9 ×5/18= 20/81 学习愉快！