MskProdComputing

Year 7 · Y7.2 Programming Essentials in Scratch · Lesson 1

Stretch tasks Sequence

Task 1

Quiz Challenge

A quiz game against four computer players, then short and long written answers.

  1. Quiz Blitz12 questions against the clock
  2. Quick Fire4 short answers
  3. Big Think2 long answers

About 20 minutes

Task 2

This or That

Pixel the cat asks 8 questions. Each has two answers: pick the right one.

  • Two answers to every question
  • A fish treat for every right answer
  • Streaks win Pixel shades, then a party hat

About 4 minutes

Task 3

Memory Match

Flip the cards two at a time to match each block card to its meaning card.

  • 12 cards: each block has a meaning
  • One peek at every card
  • Combo points for pairs found in a row

6 pairs, about 4 minutes

The games need JavaScript. Every question is below, with the answers at the end.

Read the lesson: Sequence

Sequence: the questions

Quiz Challenge, round 1: Quiz Blitz

  1. What is a sequence?

    • A choice between two paths
    • A named box that stores a value
    • Instructions carried out in order, one after another
    • Instructions that repeat forever

  2. Computers work out what you meant, even if your instructions are in the wrong order.

    • True
    • False

  3. The sprite starts facing right. Which way is it facing at the end?

    when green flag clicked
turn right 90 degrees
turn right 90 degrees
    • Left
    • Right
    • Up
    • Down

  4. Put the blocks in order: the sprite says hello, walks forward, then says goodbye.

    Number these 1 to 4.

    • say Hello! for 2 seconds
    • move 100 steps
    • say Goodbye! for 2 seconds
    • when green flag clicked

  5. Two blocks are swapped, so the sprite moves before it turns instead of after. What happens?

    • It ends up somewhere different
    • Nothing changes
    • Scratch fixes the order
    • The program crashes

  6. The sprite starts in the middle, facing right. How far right of the middle does it end up?

    when green flag clicked
move 50 steps
move 30 steps
move -20 steps
    • 100 steps
    • 80 steps
    • 20 steps
    • 60 steps

  7. Putting the right steps in the wrong order is just as wrong as having the wrong steps.

    • True
    • False

  8. Which block should come first in most Scratch scripts?

    • move 10 steps
    • say Hello!
    • turn right 90 degrees
    • when green flag clicked

  9. Instructions carried out in order, one after another, are called what? One word.

  10. A robot is told: put on your shoes, then put on your socks. What goes wrong?

    • The socks end up over the shoes
    • Nothing: the order does not matter
    • The robot refuses to start
    • The shoes disappear

  11. What does the sprite say last?

    when green flag clicked
say "Ready" for 1 seconds
say "Steady" for 1 seconds
say "Go!" for 1 seconds
    • Go!
    • Ready
    • Steady
    • Nothing

  12. Which TWO are true about a computer following a sequence?

    Tick 2.

    • It follows the steps exactly as written
    • It does the steps in the order given
    • It skips steps that look wrong
    • It guesses what you meant
    • It picks the best order itself

Quiz Challenge, round 2: Quick Fire

  1. What is a sequence in programming? [2 marks]

  2. Explain why computers are described as extremely literal. [2 marks]

  3. Two blocks in a script are swapped. Explain why the sprite might end up in a different place. [2 marks]

  4. A recipe is an example of a sequence. Explain why. [2 marks]

Quiz Challenge, round 3: Big Think

  1. Explain why the order of blocks in a Scratch script matters. Use an example. [4 marks]

  2. Compare giving instructions to a person and giving instructions to a computer. [6 marks]

This or That: tick the right answer

  1. Which of these is a sequence?

    • Steps repeated over and over
    • Steps carried out one after another

  2. Do computers guess what you meant?

    • Yes: they fix obvious mistakes
    • No: they do exactly what you say

  3. What does the sprite say first?

    say "Hi" for 1 seconds
say "Bye" for 1 seconds
    • Bye
    • Hi

  4. The steps are all right, but in the wrong order. Is the program right?

    • Yes: the steps are all there
    • No: order is part of the instruction

  5. The sprite faces right and turns right 90 degrees. Which way does it face now?

    • Up
    • Down

  6. A sprite moves 30 steps, then 30 more. How far has it moved?

    • 30 steps
    • 60 steps

  7. Which block usually starts a script?

    • when green flag clicked
    • move 10 steps

  8. Why might a program that looks right still do something ridiculous?

    • The computer ignored some blocks
    • Its steps are in the wrong order

Memory Match: match each block to its meaning

BlockMeaning
A move 100 steps1 Starts the script
B move -20 steps2 Shows a speech bubble for a while
C turn right 90 degrees3 Moves the sprite backwards
D turn left 90 degrees4 A quarter turn clockwise
E say Hello! for 2 seconds5 Moves the sprite forward
F when green flag clicked6 A quarter turn anticlockwise
Answers

Round 1: Quiz Blitz

  1. Instructions carried out in order, one after another A sequence runs its steps in order. Repeating is iteration and choosing is selection.
  2. False Computers are extremely literal: they do exactly what you say, in exactly the order you say it.
  3. Left Each turn is a quarter turn clockwise: from right to down, then from down to left.
  4. when green flag clicked → say Hello! for 2 seconds → move 100 steps → say Goodbye! for 2 seconds The event comes first, then the steps in exactly the order they should happen.
  5. It ends up somewhere different Order is part of the instruction: the same steps in a different order give a different result.
  6. 60 steps 50 + 30 - 20 = 60. A negative number of steps moves the sprite backwards.
  7. True Order is part of the instruction.
  8. when green flag clicked An event block such as when green flag clicked starts the script running.
  9. sequence That is a sequence, the most basic building block of every program.
  10. The socks end up over the shoes A computer follows the exact order it is given, even when the result makes no sense.
  11. Go! The blocks run from the top down, so Go! comes last.
  12. It follows the steps exactly as written; It does the steps in the order given Computers are literal: the exact steps, in the exact order.

Round 2: Quick Fire

    • A set of instructions
    • Carried out in order, one after another
    Model answer

    A sequence is a set of instructions carried out in order, one after another.

    • They do exactly what they are told
    • They cannot guess what you meant or fix your mistakes
    Model answer

    Computers do exactly what you tell them, in exactly the order you say it. They cannot guess what you meant, so a small mistake in the instructions gives a wrong result.

    • The steps now happen in a different order
    • Each step starts from where the step before it finished
    Model answer

    The steps now happen in a different order. Each step starts from where the previous one finished, so turning before moving sends the sprite in another direction.

    • It is a list of steps or instructions
    • They must be followed in order
    Model answer

    A recipe is a list of steps that must be followed in order, one after another. Doing them in a different order, such as icing the cake before baking it, gives the wrong result.

Round 3: Big Think

    • Blocks run one after another, from top to bottom
    • The computer does exactly what it is told
    • Swapping blocks changes where the sprite ends up
    • An example, such as moving before turning instead of after
    • The right steps in the wrong order are still wrong
    Model answer

    The blocks run one after another, from top to bottom, and the computer does exactly what it is told. If two blocks are swapped, the sprite can end up somewhere else. For example, moving before turning sends the sprite forward first, but turning before moving sends it off in a new direction. The right steps in the wrong order are just as wrong as the wrong steps.

    • A person can guess what you meant
    • A person can spot an obvious mistake, fix it or ask
    • A computer does exactly what it is told
    • A computer follows the exact order given
    • A computer will not notice a mistake, so it can do something silly
    • So instructions for a computer must be precise, with every step included
    • A suitable example
    Model answer

    A person can often guess what you meant, and they can spot an obvious mistake and fix it or ask a question. A computer is literal: it does exactly what it is told, in the exact order given, one after another. It will not notice a mistake, so it can do something ridiculous, for example walking straight into a wall. This means instructions for a computer must be precise, with every step included in the right order.

This or That

  1. Steps carried out one after another A sequence runs its steps in order. Repeating is iteration.
  2. No: they do exactly what you say Computers are extremely literal. They follow the instructions exactly as given.
  3. Hi Blocks run from the top down, so Hi comes first.
  4. No: order is part of the instruction Putting the right steps in the wrong order is just as wrong as having the wrong steps.
  5. Down Turning right, clockwise, from facing right points the sprite down the screen.
  6. 60 steps Each move happens in turn, so they add up: 30 + 30 = 60.
  7. when green flag clicked An event block such as when green flag clicked starts the script running.
  8. Its steps are in the wrong order Computers follow every step in exactly the order given, so a wrong order gives a strange result.

Memory Match

  • A 5 move 100 steps: Moves the sprite forward
  • B 3 move -20 steps: Moves the sprite backwards
  • C 4 turn right 90 degrees: A quarter turn clockwise
  • D 6 turn left 90 degrees: A quarter turn anticlockwise
  • E 2 say Hello! for 2 seconds: Shows a speech bubble for a while
  • F 1 when green flag clicked: Starts the script