Question 4

Create a folder/directory Question4 for your new program.

The algorithm, represented using pseudo-code in Figure 4, and the variable table, Table 3, describe a program that calculates and displays all of the prime numbers between 2 and 50, inclusive.

The MOD operator calculates the remainder resulting from an integer division eg 10 MOD 3 = 1.

If you are unsure how to use the MOD operator in the programming language you are using, there are examples of it being used in the Skeleton Program.

Figure 4

OUTPUT "The first few prime numbers are:"
FOR Count1 = 2 TO 50 DO
Count2 = 2
Prime = "Yes"
WHILE Count2 * Count2 <= Count1 DO
IF (Count1 MOD Count2 = 0) THEN
Prime = "No"
ENDIF
Count2 = Count2 + 1
ENDWHILE
IF Prime = "Yes" THEN
OUTPUT Count1
ENDIF
ENDFOR

Table 3

Identifier Data Type Purpose
Count1 Integer Stores the number currently being checked for primeness
Count2 Integer Stores a number that is being checked to see if it is a factor of Count1
Prime String Indicates if the value stored in Count1 is a prime number or not

What you need to do

Write a program for the algorithm in Figure 4. Run the program and test that it works correctly. Save the program in your new Question4 folder/directory.

11 Marks

+ 1 Mark for testing screenshot