การเขียนเศษส่วนในรูปทศนิยม

3 = 0.3, 9 = 0.9, 7 = 0.7 10 10 10 15 = 0.15, 37 = 0.37, 68 = 0.68 100 100 100 275 = 0.275, 757 = 0.757 , 549 = 0.549 1000 1000 1000

3 5 6 10

3 5 6 10 3= 6 5 10 6 10 3 5

3 1 5 2 3 = 3×2 = 6 1 = 1×5 = 5 5 5×2 10 2 2×5 10 3 5 1 2

9 3 25 20 3 = 3×4 = 12 9 = 9×5 = 45 20 20×5 100 25 25×4 100 3 9 25 20

7 231 500 200 7 = 7×2 = 14 231 = 231×5 = 1155 500 500×2 1000 200 200×5 1000 7 231 500 200