1. 
47.3  23.7 
Explanation: 

06.1
47.3
23.7
23.6 

The decimal places are lined up and each number has the same number of decimal places, so the numbers are ready to be subtracted.
Place the decimal in your answer directly under the decimals in the problem. 
2. 
147.23  86.57 
Explanation: 

146111
147.23
86.57
60.66 

Write your numbers, making sure that you line up the decimals.
Subtract the numbers as if they were whole numbers.
Place the decimal in your answer directly under the decimals in the problem. 
3. 
46.5  24.37 
Explanation: 

46.41
46.50
24.37
22.13 

Write your numbers, making sure that you line up the decimals.
Add one zero to 46.5 so that both numbers have the same number of decimal places.
Subtract the numbers as if they were whole numbers.
Place the decimal in your answer directly under the decimals in the problem. 
4. 
546.725  376.47 
Explanation: 

4160610
546.725
376.470
170.255 

Write your numbers, making sure that you line up the decimals.
Add one zero to 376.47 so that both numbers have the same number of decimal places.
Subtract the numbers as if they were whole numbers.
Place the decimal in your answer directly under the decimals in the problem. 
5. 
97  43.76 
Explanation: 

96091
97.00
43.76
53.24 

Make 97 a decimal by placing a decimal point on the right for 97.
Add two zeroes to 97. so that both numbers have two decimal places.
Subtract the numbers as if they were whole numbers.
Place the decimal in your answer directly under the decimals in the problem. 
6. 
987.65  769 
Explanation: 

971.65
987.65
769.00
218.65 

Make 769 a decimal by placing a decimal point on the right for 769.
Add two zeroes to 769. so that both numbers have two decimal places.
Subtract the numbers as if they were whole numbers.
Place the decimal in your answer directly under the decimals in the problem. 