Set and change variable blocks
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which block puts a starting value into the score variable at the start of a game?
2. What does 'change score by 1' do when score is 4?
3. Which block makes the score jump back to 0 for a new game?
4. A player loses a life. Lives is 3. Which block makes lives go DOWN to 2?
5. Where should 'set score to 0' usually go in a script?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1set score to 0 | Aset lives to 3 | |
| 2change score by 1 | Bchange lives by -1 | |
| 3Counting down: take 1 life away each time the player is hit | CThe score was never set to 0 at the start, so it keeps the old value from the last game and the count will be wrong. Add set score to 0 first. | |
| 4Setting at the start: give lives a starting value of 3 when the game begins | DAdds 1 to the number already stored in score, so the score counts up. | |
| 5when green flag clicked change score by 1 (no set block first) | EThe set block replaces the score with 1 every time instead of adding to it. Use change score by 1 to count up. | |
| 6set score to 1 (used to add a point each time a coin is touched) | FStores the starting value 0 in the score variable, so the game begins with a score of zero. |
C
Definitions
set score to 0
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
___ score to 0
change score by 1
2.
when green flag clicked
set score to _
3.
when space key pressed
______ score by 1
4.
set lives to 3
change lives by __
5.
when this sprite clicked
change _____ by 1
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
when green flag clicked
B
set score to 0
C
change score to 1
D
say score
Question 2
A
set score by 0
B
change score by 1
C
change score by 1
D
say score
Question 3
A
when green flag clicked
B
change lives by 3
C
change lives by -1
D
say lives
Question 4
A
when green flag clicked
B
set score to 0
C
change score by 1
D
change points by 1
E
say score
Question 5
A
when green flag clicked
B
set timer to 10
C
change timer by 1
D
say timer
Answer Key
Set and change variable blocks
Section A: Quick Questions
Q1
A — set score to 0
Q2
B — Score becomes 5
Q3
B — set score to 0
Q4
A — change lives by -1
Q5
A — Near the start, under the green flag
Section B: Match the Pairs
Q1
set score to 0 → Stores the starting value 0 in the score variable, so the game begins with a score of zero.
Q2
change score by 1 → Adds 1 to the number already stored in score, so the score counts up.
Q3
Counting down: take 1 life away each time the player is hit → change lives by -1
Q4
Setting at the start: give lives a starting value of 3 when the game begins → set lives to 3
Q5
when green flag clicked
change score by 1
(no set block first) → The score was never set to 0 at the start, so it keeps the old value from the last game and the count will be wrong. Add set score to 0 first.
Q6
set score to 1
(used to add a point each time a coin is touched) → The set block replaces the score with 1 every time instead of adding to it. Use change score by 1 to count up.
Section C: Definitions
Q1
set score to 0 — A variable block that stores a starting value in score. Use change score by 1 to add to it, or by -1 to take away, so the score counts up or down.Section D: Fill in the Blanks
Q1
set score to 0
change score by 1Q2
when green flag clicked
set score to 0Q3
when space key pressed
change score by 1Q4
set lives to 3
change lives by -1Q5
when this sprite clicked
change score by 1Section E: Spot the Error
Q1
C — The change block adds to a variable, so it must say 'by'. It should be 'change score by 1'. The word 'to' belongs in the set block.
Q2
A — The set block stores a starting value, so it uses 'to'. It should be 'set score to 0'. The word 'by' belongs in the change block.
Q3
B — At the start, lives needs a starting value, so this line should use a set block: 'set lives to 3'. A change block only adds to what is already stored.
Q4
D — The program uses a variable called score, but this line changes a different variable called points. It should be 'change score by 1' so the score keeps counting up.
Q5
C — A countdown needs to take away from the timer. Changing by 1 adds, so the timer would count up. It should be 'change timer by -1'.