Times-Table Challenge III

Review — where we got to 5 min

• reset timer starts the clock. (round ((60) - (timer))) shows the time left.
• repeat until <<(timer) > (60)> or <(lives) = (0)>> ends the round by itself.
• The clock has its own script, so it ticks while you type.

Quick-fire

Right now every right answer is worth 1 point. Ten right in a row is 10 points. Is that fair to someone who never slipped?

Today’s Topic 3 min

• A streak variable, and change [score v] by (streak)
• A level chosen first, kept in min and max
• A coin toss with <(pick random (1) to (2)) = [1]> for × or +
• broadcast [new question v] and wait — one script makes the question

Learning outcome

By the end of this lesson you will be able to:

1. Keep a streak that grows, and resets to 0 on a mistake.
2. Ask for a level first, and use it in every question.
3. Mix two kinds of question, with the right answer kept in one place.

Learnt — streak, level, mix 28 min

1 · A streak

A streak counts right answers in a row. One wrong answer sends it back to 0.

Now make each right answer worth the streak. Watch the points grow:

In blocks it is four lines inside the if / else you already have:

if <(answer) = (correct)> then
  change [streak v] by (1)
  change [score v] by (streak)
else
  set [streak v] to (0)
  change [lives v] by (-1)
end
            

A practice Robot shows it best. It answers by itself, and it is right about three times in four:

when flag clicked
set [score v] to (0)
set [streak v] to (0)
repeat (12)
  if <(pick random (1) to (4)) > (1)> then
    say [Right!] for (1) seconds
    change [streak v] by (1)
    change [score v] by (streak)
  else
    say [Wrong!] for (1) seconds
    set [streak v] to (0)
  end
end
            

Three kinds of variable

2 · Choose a level first

A six-year-old and a twelve-year-old should not get the same questions. Ask first, and keep the answer in two numbers: the smallest and the biggest allowed.

1. Make two variables, min and max.
2. At the top of the flag script, add ask [Easy or hard?] and wait.
3. Add an if / else with <(answer) = [hard]>.
4. Hard sets min to 2 and max to 12. Easy sets 1 and 5.
5. In both set blocks for a and b, drop (min) and (max) into pick random.

when flag clicked
ask [Easy or hard?] and wait
if <(answer) = [hard]> then
  set [min v] to (2)
  set [max v] to (12)
else
  set [min v] to (1)
  set [max v] to (5)
end
repeat (3)
  set [a v] to (pick random (min) to (max))
  set [b v] to (pick random (min) to (max))
  say (join (a) (join [ × ] (b))) for (2) seconds
end
            

3 · A mix of × and +

Let the program toss a coin. (pick random (1) to (2)) gives 1 or 2, like heads or tails. 1 means a times question. 2 means a plus question.

Here is the smart part. Work out the right answer in the same place you build the question. Keep it in a variable called correct.

when I receive [new question v]
set [a v] to (pick random (1) to (10))
set [b v] to (pick random (1) to (10))
if <(pick random (1) to (2)) = [1]> then
  set [question v] to (join (a) (join [ × ] (b)))
  set [correct v] to ((a) * (b))
else
  set [question v] to (join (a) (join [ + ] (b)))
  set [correct v] to ((a) + (b))
end
            

Now the round needs just one check, whatever the sign:

broadcast [new question v] and wait
ask (question) and wait
if <(answer) = (correct)> then
end
            

when flag clicked
repeat (6)
  broadcast [new question v] and wait
  say (join (question) (join [ = ] (correct))) for (2) seconds
end
            

Basic — streak, level and mix in your game 25 min

Open your sixty-second game. You will end with four scripts on the Wizard.

Step 1 — five new variables

1. Make streak, min, max, question and correct.
2. Leave streak ticked. Untick the others.

Step 2 — the question maker

1. Build the when I receive [new question v] script from Learnt 3.
2. Use (min) and (max) in both pick random blocks.

Step 3 — split the flag script

1. Pull everything from reset timer down off the flag script.
2. Put when I receive [play v] on top of it.
3. The flag script now asks the level, sets score, streak and lives, then broadcasts play.

Step 4 — the new round

1. Inside the loop, replace the two set blocks with broadcast [new question v] and wait.
2. Ask (question). Check against (correct).
3. Add the streak blocks to both halves of the if / else.

Step 5 — play it three ways

1. Play on easy. Get five right in a row. Watch score jump.
2. Play on hard. Check no number is below 2 or above 12.
3. Get one wrong on purpose. Check streak goes to 0.

when flag clicked
ask [Easy or hard?] and wait
if <(answer) = [hard]> then
  set [min v] to (2)
  set [max v] to (12)
else
  set [min v] to (1)
  set [max v] to (5)
end
set [score v] to (0)
set [streak v] to (0)
set [lives v] to (3)
broadcast [play v]
              

when I receive [play v]
reset timer
broadcast [clock v]
repeat until <<(timer) > (60)> or <(lives) = (0)>>
  broadcast [new question v] and wait
  ask (question) and wait
  if <(answer) = (correct)> then
    change [streak v] by (1)
    change [score v] by (streak)
  else
    set [streak v] to (0)
    change [lives v] by (-1)
    say (join [It is ] (correct)) for (1) seconds
  end
end
say (join [Round over! Score: ] (score)) for (4) seconds
              

The question maker is the one in Learnt 3, with (min) and (max) in the pick random blocks. The clock is last lesson’s, unchanged.

Shout the streak

Make the Wizard cheer when a streak gets going.

• At a streak of 3, he says “3 in a row!”.
• At a streak of 5, he says “5 in a row! On fire!”.
• Other right answers get no cheer.

change [streak v] by (1)
change [score v] by (streak)
if <(streak) = (3)> then
  say [3 in a row!] for (1) seconds
end
if <(streak) = (5)> then
  say [5 in a row! On fire!] for (1) seconds
end
            

A medium level

Add a level between easy and hard.

• The question becomes “Easy, medium or hard?”.
• Medium uses numbers from 2 to 9.
• Easy and hard still work as before.

ask [Easy, medium or hard?] and wait
if <(answer) = [hard]> then
  set [min v] to (2)
  set [max v] to (12)
else
  if <(answer) = [medium]> then
    set [min v] to (2)
    set [max v] to (9)
  else
    set [min v] to (1)
    set [max v] to (5)
  end
end
            

Take-away, never below zero

Add a third kind of question: take-away. The answer must never be below zero.

• About one question in three is a take-away.
• The big number always comes first.
• The check still uses correct, so the round does not change.

when flag clicked
repeat (6)
  set [a v] to (pick random (1) to (10))
  set [b v] to (pick random (1) to (10))
  set [big v] to ((a) + (b))
  say (join (big) (join [ - ] (join (b) (join [ = ] (a))))) for (2) seconds
end
            

set [big v] to ((a) + (b))
set [question v] to (join (big) (join [ - ] (b)))
set [correct v] to (a)
            

Hard is worth double

A streak on hard should be worth more than the same streak on easy.

• On hard, each right answer scores the streak times 2.
• On easy, it scores the streak, as now.
• The end of the round also says your best streak.

if <(answer) = (correct)> then
  change [streak v] by (1)
  change [score v] by ((streak) * (bonus))
  if <(streak) > (best streak)> then
    set [best streak v] to (streak)
  end
else
  set [streak v] to (0)
  change [lives v] by (-1)
end
            

Summary 4 min

Today the round got deeper without getting longer.

1. A streak grows on a right answer and goes to 0 on a wrong one.
2. change [score v] by (streak) makes long streaks pay.
3. A level chosen first sets min and max for every question.
4. The question maker builds the question and correct together, so the round has one check.

Streak

How many right answers in a row, since the last mistake.

Level

How hard the game is. Here, how big the numbers are.

Coin toss

A pick random between 1 and 2. Each has an even chance.

And wait

Makes a broadcast wait until every script it started has finished.

Next lesson: the last of the arc. A menu with buttons, a best score that is never wiped, and a results card in words.