《2025年通城学典计算能手四年级数学下册青岛版》

一、解方程。

10.5 + x + 21 = 56 x + 2x + 18 = 78 5x + 12.5 = 32.3
0.4×7 + 4x = 3.2 x÷1.5 - 1.38 = 0.62 8x - 2.6×6 = 5.2
6x + 15.8 = 18.8 (x - 4)÷2 = 8.5 13.8x + 8.4x = 33.3
15x - 12x = 8.7 3.4x - 20 = 54.8 4.2x + 2.5x = 134
1.3x + 7.2 = 12.4 x÷0.8 - 0.75 = 0.75 8(x - 6.2) = 41.6

答案： x = 24.5 x = 20x = 3.96x = 0.1 x = 3x = 2.6x = 0.5 x = 21x = 1.5x = 2.9 x = 22x = 20x = 4 x = 1.2x = 11.4

### 二、计算下面各题，怎样简便就怎样计算。

2.46×1.1 - 1.71 - 0.29 0.75×18÷0.15 - 6.8 2.89 + 24.5÷(2.2 - 1.5)
8×(12.5 + 2.5)×0.4 29.2 - 3.9×2.4 - 0.64 31.45 - 21.7÷12.5÷0.8
4.57 + 3.17 + 3.43 + 5.83 37.8×27 - 7.8×27 8.37×0.2 + 8.37×7 + 8.37
427÷7×(13 + 8) 3.24×10.3 - 3×0.324 8×4.6 + 3.5×8 + 4.4×8
(22.6 + 54.4÷8.5)×0.6 2.8÷[(7.3 - 4.5)×0.4] 21.5÷(5.26 - 0.96)×0.1

答案： 0.706 83.2 37.8948 19.2 29.2817 810 83.71281 32.4 10017.4 2.5 0.5