0,8+3/7= 8/10+3/7=56/70+30\70=86/70=1 16/70=1 8/35
3 1/3- 2,5 = 10/3 - 25/10 = 100/30 - 75/30 = 25/30= 5/6
4,9 +1 1/9 = 49/10 +10/9 = 441/90 + 100/90 = 541/90 = 6 1/90
26 1/11 - 5,7= 287/11 - 57/10 = 2870/110 - 627/110= 2243/110 = 20 39/110
5 * 162 + 5 * 38 = 5 * (162 +38) = 5 * 200 = 1.000
30 * 777 + 123 * 30 = 30 * (777 + 123) = 30 * 900 = 27.000
734 * 14 + 266 * 14 = 14 * (734 + 266) = 14 * 1.000 = 14.000
4 пример написан не полностью.
1м 7дм=17дм
51см=5дм 1см
42дм=4м 2дм