6. 40-6=34 34:2= 17
7. 75-17= 58 58:2=29
8․ 3+7 = 10 10×2=20 20-8=12 12×10 = 120
9. 140 – 20 = 120 120:20 = 6
10. 65+5 = 70 70×5 = 350
6. 40-6=34 34:2= 17
7. 75-17= 58 58:2=29
8․ 3+7 = 10 10×2=20 20-8=12 12×10 = 120
9. 140 – 20 = 120 120:20 = 6
10. 65+5 = 70 70×5 = 350