A clock is 5 minutes fast. What time does it show? What time does another clock show if it is 50 minutes slow?

The hour hand is just past the 8, and the minute hand is on the 12. This indicates $8:00$.

The clock shows $8:00$, which is 5 minutes after $7:55$.
The clock is $8:00 - 7:55 = 5$ minutes fast.
The clock is $\boxed{\text{5 minutes fast}}$.

30-31) Clock 2

The hour hand is just past the 7, and the minute hand is on the 1. This indicates $7:05$.

The clock shows $7:05$, which is 50 minutes before $7:55$.
The clock is $7:55 - 7:05 = 50$ minutes slow.
The clock is $\boxed{\text{50 minutes slow}}$.

32-33) Clock 3

The hour hand is between 8 and 9, and the minute hand is on the 3. This indicates $8:15$.

The clock shows $8:15$, which is 20 minutes after $7:55$.
The clock is $8:15 - 7:55 = 20$ minutes fast.
The clock is $\boxed{\text{20 minutes fast}}$.

34-35) Clock 4

The hour hand is between 7 and 8, and the minute hand is on the 6. This indicates $7:30$.

The clock shows $7:30$, which is 25 minutes before $7:55$.
The clock is $7:55 - 7:30 = 25$ minutes slow.
The clock is $\boxed{\text{25 minutes slow}}$.

36) What needs to be added/subtracted to change 7812 to 7212?

Since the result is negative, 600 needs to be subtracted.
$\boxed{\text{600 subtracted}}$.

37) What needs to be added/subtracted to change 6324 to 6354?

Since the result is positive, 30 needs to be added.
$\boxed{\text{30 added}}$.

38) What is the largest number you can make with these digits: 2, 5, 8, 6, 5?

The digits are $8, 6, 5, 5, 2$.
The largest number is $\boxed{\text{86552}}$.

39) Now write it in words.
The number 86552 in words is $\boxed{\text{Eighty-six thousand, five hundred and fifty-two}}$.

40) Write in figures four thousand, one hundred and twenty.

Four thousand $= 4000$
One hundred $= 100$
Twenty $= 20$

The number in figures is $\boxed{\text{4120}}$.