If the ones digit of a number greater than 1 is 0,what factor or factors must that number have

If the units digit is zero, then you have an even number ...
' 2 ' must be one of its factors.

It must also have two or more places ... it's greater than 9.
If it had only one place, and its units digit were zero, then
the whole thing would be zero.

Since it has two or more places,  5  and  10  are also factors.

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post