Math's problem

There are 172 students at Glenbrae School. On Wednesday, 67 students were out of school. How many students were left at school?

This is how I solved The problem:

So there are 172 and 67
172 - 67

So you take away the 2 and the 7 from the hundred and the ten which makes 170 and 60

170 - 60= 110
You then do a take away in between which makes 110
Then you bring back the 7 and 2, you also put a takeaway in between the 7

7-2=5
Which makes 5
Then you do 110 take away 5

110-5=105

This means the answer is 105