Range check

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. A range check on Age allows values from 0 to 120. Which condition accepts a valid age?

A IF Age >= 0 AND Age <= 120

B IF Age >= 0 OR Age <= 120

2. What does a range check test?

A The value lies between a lowest and a highest allowed value

B The value has been typed in twice with the same result

3. A mark must be between 0 and 100 inclusive. Is a mark of 100 accepted by IF Mark >= 0 AND Mark <= 100?

A No, 100 is rejected because it is on the limit

B Yes, 100 is accepted because <= includes the limit

4. Which condition is TRUE when a mark is outside the range 0 to 100?

A Mark < 0 OR Mark > 100

B Mark < 0 AND Mark > 100

5. A range check allows 1 to 31 for the day of a month. Which condition wrongly rejects the valid value 31?

A IF Day >= 1 AND Day <= 31

B IF Day >= 1 AND Day < 31

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1IF Mark >= 0 AND Mark <= 100 THEN		ATests whether Age is outside the allowed range, so the value is rejected
2IF Age < 0 OR Age > 120 THEN		BIF Score >= 1 AND Score <= 10 THEN
3A range check on a date: the month number must be between 1 and 12, and 1 and 12 are valid		CIF Month >= 1 AND Month <= 12 THEN
4Both limits must be true for a number to pass, so the two tests are joined with AND		DThe limits 0 and 100 are wrongly rejected because > and < are used. It should be >= and <= so the limits are accepted.
5IF Age >= 0 OR Age <= 120 THEN		EOR is used to join the limits, so every number passes, because any number is either at least 0 or at most 120. It should be AND.
6IF Mark > 0 AND Mark < 100 THEN		FRange check: accepts a Mark from 0 to 100, including 0 and 100 themselves

Definitions

IF Age >= 0 AND Age <= 120

Fill in the Blanks

Complete each line of code by filling in the missing parts.

IF Age >= 0 ___ Age <= 120 THEN OUTPUT "Age accepted" ENDIF

IF Age >= 0 AND Age __ 120 THEN OUTPUT "Age accepted" ENDIF

IF Age < 0 __ Age > 120 THEN OUTPUT "Invalid age" ENDIF

IF Score __ 0 AND Score <= 100 THEN OUTPUT "Valid score" ENDIF

IF Month >= 1 AND _____ <= 12 THEN OUTPUT "Valid month" ENDIF

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A IF Age >= 0 OR Age <= 120

B THEN

C OUTPUT "Valid"

D ENDIF

Question 2

A INPUT Mark

B IF Mark >= 0 AND Mark <= 100

C THEN OUTPUT "Rejected"

D ELSE OUTPUT "Rejected"

E ENDIF

Question 3

A INPUT Temp

B IF Temp < -10 OR Temp > 40

C THEN OUTPUT "Outside range"

D ELSE OUTPUT "Outside range"

E ENDIF

Question 4

A INPUT Rating

B IF Rating > 1 AND Rating <= 5

C THEN OUTPUT "Accepted"

D ENDIF

Question 5

A OUTPUT "Enter mark 0-100"

B INPUT Mark

C WHILE Mark < 0 AND Mark > 100

D INPUT Mark

E ENDWHILE

Answer Key

Range check

Section A: Quick Questions

A — IF Age >= 0 AND Age <= 120

A — The value lies between a lowest and a highest allowed value

B — Yes, 100 is accepted because <= includes the limit

A — Mark < 0 OR Mark > 100

B — IF Day >= 1 AND Day < 31

Section B: Match the Pairs

IF Mark >= 0 AND Mark <= 100 THEN → Range check: accepts a Mark from 0 to 100, including 0 and 100 themselves

IF Age < 0 OR Age > 120 THEN → Tests whether Age is outside the allowed range, so the value is rejected

A range check on a date: the month number must be between 1 and 12, and 1 and 12 are valid → IF Month >= 1 AND Month <= 12 THEN

Both limits must be true for a number to pass, so the two tests are joined with AND → IF Score >= 1 AND Score <= 10 THEN

IF Age >= 0 OR Age <= 120 THEN → OR is used to join the limits, so every number passes, because any number is either at least 0 or at most 120. It should be AND.

IF Mark > 0 AND Mark < 100 THEN → The limits 0 and 100 are wrongly rejected because > and < are used. It should be >= and <= so the limits are accepted.

Section C: Definitions

IF Age >= 0 AND Age <= 120 — A range check tests that a value lies between the lowest and highest allowed values. The limits themselves are accepted. AND joins both limits.

Section D: Fill in the Blanks

IF Age >= 0 AND Age <= 120 THEN
   OUTPUT "Age accepted"
ENDIF

IF Age >= 0 AND Age <= 120 THEN
   OUTPUT "Age accepted"
ENDIF

IF Age < 0 OR Age > 120 THEN
   OUTPUT "Invalid age"
ENDIF

IF Score >= 0 AND Score <= 100 THEN
   OUTPUT "Valid score"
ENDIF

IF Month >= 1 AND Month <= 12 THEN
   OUTPUT "Valid month"
ENDIF

Section E: Spot the Error

A — A range check needs AND so the value must meet both limits. With OR, every number passes, even -5 or 500. It should be IF Age >= 0 AND Age <= 120.

C — The THEN branch runs when the mark is inside the range, so it should output "Accepted". Here, valid marks would be rejected.

D — The condition tests for being outside the range, so ELSE means the value is inside it. It should output "In range", not "Outside range".

B — Values on the limits must be accepted. Using > 1 rejects a rating of 1, which is the lowest allowed value. It should be Rating >= 1.

C — A number cannot be below 0 and above 100 at the same time, so the loop would never run. To catch values outside the range, use OR: WHILE Mark < 0 OR Mark > 100.