Totalling in a loop (7a)
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Where should a running total be set to 0?
2. Which statement adds the value in Number to a running total?
3. A loop adds 4, 6 and 10 to a total that started at 0. What does OUTPUT Total show after the loop?
4. Which pseudocode correctly totals 5 numbers typed in by the user?
5. When should OUTPUT Total be placed to show the final total only?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1Total ← 0 | ATotal ← Value replaces the total with the latest value instead of adding to it, so nothing is totalled. | |
| 2Total ← Total + Value | BFOR Count ← 1 TO 5 INPUT Value Total ← Total + Value NEXT Count | |
| 3Add each number the user enters to the running total inside a FOR loop | CTotal is set to 0 inside the loop, so it is reset on every repeat and only the last value is kept. | |
| 4Output the final total once, after the loop has finished | DAdds the current Value to the running total on each repeat of the loop. | |
| 5FOR Count ← 1 TO 5 Total ← 0 INPUT Value Total ← Total + Value NEXT Count | EInitialises the running total to zero before the loop starts, so no old value is left in it. | |
| 6FOR Count ← 1 TO 5 INPUT Value Total ← Value NEXT Count | FNEXT Count OUTPUT Total |
C
Definitions
Total ← Total + Value
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
Total ← _
WHILE Count < 5 DO
Total ← Total + Value
2.
FOR Count ← 1 TO 5
Total ← _____ + Value
NEXT Count
3.
FOR Count ← 1 TO 5
INPUT Value
Total ← Total _ Value
4.
Total ← Total + Value
NEXT Count
______ Total
5.
INPUT Value
Total ← Total + Value
____ Count
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
Total ← 1
B
FOR Count ← 1 TO 5
C
INPUT Value
D
Total ← Total + Value
E
NEXT Count
F
OUTPUT Total
Question 2
A
Total ← 0
B
FOR Count ← 1 TO 4
C
INPUT Total
D
Total ← Total + Value
E
NEXT Count
F
OUTPUT Total
Question 3
A
Total ← 0
B
FOR Count = 1 TO 5
C
INPUT Mark
D
Total ← Total + Mark
E
NEXT Count
F
OUTPUT Total
Question 4
A
Total = 0
B
FOR Day ← 1 TO 7
C
INPUT Steps
D
Total ← Total + Steps
E
NEXT Day
F
OUTPUT Total
Question 5
A
Total ← 0
B
REPEAT
C
OUTPUT Value
D
Total ← Total + Value
E
UNTIL Value = 0
F
OUTPUT Total
Answer Key
Totalling in a loop (7a)
Section A: Quick Questions
Q1
B — Before the loop starts
Q2
A — Total ← Total + Number
Q3
A — 20
Q4
B — Total ← 0
FOR Count ← 1 TO 5
INPUT Number
Total ← Total + Number
NEXT Count
OUTPUT Total
Q5
A — After the loop has finished
Section B: Match the Pairs
Q1
Total ← 0 → Initialises the running total to zero before the loop starts, so no old value is left in it.
Q2
Total ← Total + Value → Adds the current Value to the running total on each repeat of the loop.
Q3
Add each number the user enters to the running total inside a FOR loop → FOR Count ← 1 TO 5
INPUT Value
Total ← Total + Value
NEXT Count
Q4
Output the final total once, after the loop has finished → NEXT Count
OUTPUT Total
Q5
FOR Count ← 1 TO 5
Total ← 0
INPUT Value
Total ← Total + Value
NEXT Count → Total is set to 0 inside the loop, so it is reset on every repeat and only the last value is kept.
Q6
FOR Count ← 1 TO 5
INPUT Value
Total ← Value
NEXT Count → Total ← Value replaces the total with the latest value instead of adding to it, so nothing is totalled.
Section C: Definitions
Q1
Total ← Total + Value — A running total: set Total to 0 before the loop, then add each Value to Total on every repeat. Output Total after the loop ends.Section D: Fill in the Blanks
Q1
Total ← 0
WHILE Count < 5 DO
Total ← Total + ValueQ2
FOR Count ← 1 TO 5
Total ← Total + Value
NEXT CountQ3
FOR Count ← 1 TO 5
INPUT Value
Total ← Total + ValueQ4
Total ← Total + Value
NEXT Count
OUTPUT TotalQ5
INPUT Value
Total ← Total + Value
NEXT CountSection E: Spot the Error
Q1
A — A running total must start at 0. Starting at 1 makes the final total 1 too big. It should be Total ← 0.
Q2
C — The input must be stored in Value. Typing into Total overwrites the running total each time. It should be INPUT Value.
Q3
B — A FOR loop sets its counter with the assignment arrow, not =. It should be FOR Count ← 1 TO 5.
Q4
A — Cambridge pseudocode uses the assignment arrow to give a variable a value. It should be Total ← 0.
Q5
C — Each repeat needs to read a new number with INPUT. OUTPUT only displays Value, so nothing new is added. It should be INPUT Value.