A tenth is 0.1, so divide 89.5 by 0.1.
89.5/0.1 multiply top and bottom by 10 to get 895/1 or just 895.
Thanks Alan,
I would look at it a little differently.
How many units are there in 75. 75 ofcourse. 75*1=75
How many hundreds are there in 1600 Well 16 of course 16*100=1600
How many thousands are there in 137000 . Ans 137 : 137*1000=137000
How many tenths in 5.7 57 because 57*1/10=5.7 (note that the 7 is in the tenths column)