1.8 or 1&4/5
To model 1.8 divided by 3, you can represent 1.8 as 18 units (since each whole number represents 10 units in this case). Then, you can divide the 18 units into 3 equal groups, each representing 1/3 of 1.8. This would result in each group having 6 units. Therefore, 1.8 divided by 3 equals 0.6 in this model.
10*18 = 180
6/10=3/5 or 12/20 or 18/30
3/10 = 9/30 = 18/60
It is impossible to answer the question without knowing what you stride is. You do not specify the units used for 18. Centimetres? Decimetres? Inches?