PROGRAMMING: END OF TOPIC REVIEW

Both use names to refer to values. A variable may change during execution, whereas a constant stays fixed during that run. A student code identifies someone rather than representing a quantity, so STRING retains its text representation, including leading zeros.

• Shared use of a name: one mark.
• Variable may change during execution: one mark.
• Constant fixed during execution: one mark.
• STRING preserves the required identifier text: one mark.

Writing focus: Address both items on a shared comparison point, then connect the type choice to the requirement.

Use an outer FOR for four accepted scores and an inner REPEAT UNTIL the current score is valid. Initialise Total once before the FOR. Add each score after acceptance because invalid attempts must not contribute. The update keeps the total so far and adds the new accepted score.

• Outer loop gives four accepted items: one mark.
• Inner retry retains current item until valid: one mark.
• Initialisation before the outer loop retains earlier contributions: one mark.
• Addition after validation excludes rejected values: one mark.

Writing focus: Use because and therefore to link placement to its effect.

Both are named routines that can receive parameters. A procedure performs a task without a function result; a function returns one value used in an expression. RETURN communicates a value, while the local declaration’s scope remains within its routine. The caller may store the result in a separate variable.

• Both named routines and may receive parameters: one mark.
• Procedure has no returned expression result: one mark.
• Function returns a value for its caller: one mark.
• Returned value does not expand the local name’s scope: one mark.

Writing focus: Distinguish the value being communicated from the name used to hold it.

DIV returns three and MOD returns two: three groups use fifteen, leaving two. The rounded random expression can return zero through six, so it includes zero and seven possible results. Under a uniform real draw, endpoints have narrower rounding intervals than interior results. It is therefore unsuitable as a guaranteed fair one-to-six die.

• Quotient three: one mark.
• Remainder two with grouping evidence: one mark.
• Possible zero and zero-to-six range: one mark.
• Reasoned rejection including interval or probability concern: one mark.

Writing focus: Show arithmetic, then make a judgement tied to the claimed use rather than merely defining RANDOM.

The outer counter visits rows one and two; for each row the inner counter visits columns one through three. Row totals are twelve and nine; grand total twenty-one. Reset RowTotal inside the outer loop before the inner loop, and GrandTotal once before the outer loop.

• Correct row-first counter sequence: one mark.
• Row totals twelve and nine: one mark.
• Grand total twenty-one: one mark.
• Correct reset locations with retention reason: one mark.

Writing focus: Tie the reset location to whether earlier columns or earlier rows must remain in the sum.

Opening FOR READ establishes access to the source; closing ends that access and releases its resources when finished. READFILE assigns the next stored item to a destination, whereas OUTPUT displays an expression. Closing does not delete the saved file or erase the working values already read.

• Open establishes READ access: one mark.
• Close ends access when finished: one mark.
• Read assignment compared with display: one mark.
• Saved file and already-read working values retained: one mark.

Writing focus: Keep the operation’s destination explicit: file to variable or expression to screen.

Use meaningful identifiers and a named constant for the repeated fixed price; relevant comments or coherent routines can also be valid improvements. Each open FOR WRITE replaces existing content, so the loop loses earlier saved items. Open once before the loop, write all intended items and close after it.

• One relevant contextual maintainability improvement: one mark.
• A second distinct contextual improvement: one mark.
• Replacement inside loop loses earlier items: one mark.
• Correct open-once write-many close-once sequence: one mark.

Writing focus: Make specific proposals and link the error to the mechanism causing data loss.

One possible solution follows. Twenty-five is rejected for the first position. Accepted scores are four, seven, two and three, giving total sixteen and mean four. The file contains those four score items in that order in the agreed format.

DECLARE Scores : ARRAY[1:4] OF INTEGER
DECLARE Position : INTEGER
DECLARE Total : INTEGER
DECLARE Average : REAL
FOR Position ← 1 TO 4
  REPEAT
    OUTPUT "Enter score from 0 to 20"
    INPUT Scores[Position]
  UNTIL (Scores[Position] >= 0) AND (Scores[Position] <= 20)
NEXT Position
Total ← 0
FOR Position ← 1 TO 4
  Total ← Total + Scores[Position]
NEXT Position
Average ← Total / 4
OUTPUT "Total: ", Total
OUTPUT "Mean: ", Average
OPENFILE "Scores.txt" FOR WRITE
FOR Position ← 1 TO 4
  WRITEFILE "Scores.txt", Scores[Position]
NEXT Position
CLOSEFILE "Scores.txt"

• Suitable array bounds and numeric declarations: one mark.
• Four positions filled using a loop and inclusive retry: one mark.
• Total initialised once and all accepted scores added: one mark.
• REAL mean and required output: one mark.
• Open WRITE once, write all elements and close: one mark.
• Correct summary values and rejected-attempt interpretation: one mark.

Writing focus: Use complete precise instructions; a description alone does not demonstrate the requested pseudocode.