I solved it!

I had to solve subtraction problems using algorithm and here it is.

WALT: solve subtraction problems using algorithm

In 1984 the men's world record for the 100m sprint was 10.02 seconds.
Today the world record for sprinting is 9.58 seconds. What is the
difference between the two records?

         9

      9 1 1

    10.02

-    9.58

     0.44

I used algorithm. The question is 10.02 minus 9.58. I took one away from the
10.02 and added to the tenths column in 10.02. Now it is 9.102 minus 9.58.
I took one away from the 0.100 and added to the 0.02, it is now 9.912 minus
9.58. 0.012 minus 0.8 equals 0.04.  0.9 minus 0.5 equals 0.4.  9.0 minus 9.0
equals 0.   0.04 plus 0.4 and 0.0 equals 0.44.

It was easy for me because I understand how to use algorithm.