1. conditionals

2. if .. then .. else .. if light is red then stop car else keep going
true or false
if light is red then stop car else keep going
happens when true
happens when false

3. if .. then .. else .. if hungry then eat else do nothing true or false
happens when true
happens when false

4. exercise
Find 2 situations in your life where you use if then else if
then
else
Situation 1
Situation 2

5. true/false maths known as Boolean algebra
a Boolean condition may be true or false or
true
false
and
true
false
not
true
false

6. exercises
► not true = ? ► not (not true) = ? ► true and false = ? ► false or true = ? ► true or (not true) = ? ► (not true) and (not false) = ? ► (not true) or (not false)= ? in doubt, use the tables…

7. inequalities
Arithmetic inequalities evaluate to true or false x < y = true if x is strictly less than y; otherwise it is false ► 1 < 0 = ? ► 0 > 1 = ? ► -10 < 1 = ? ► 5 ≤ 5 = ? ► 0 < 1 or 1 > 0 = ? ► x < x + 5 = ?

8. exercises-solve
► not (0 < 1) = ? ► not (not false) = ? ► false and true = ? ► false or (0 < 1)= ? ► true or (5 > 10) = ? ► true and (false or not false) = ?

9. true/false maths known as Boolean algebra
complete true or false tables or
true
false
and
true
false
not
true
false

10. exit task - create 1) six booleans Qs front 2) booleans answers back►

11. magic-8-ball famous fortune telling game
“think really hard about your question, ask the ball, get funny answer”

12. vocabulary
math->random(n) -> 0,1,2…., n-1 returns a number in [0,n] ie. math -> random (3) -> 0,1,2

13. question var x := math -> random (3) if x = 0 or x = 2 then
What does this do?
var x := math -> random (3)
if x = 0 or x = 2 then
1 -> post to wall
else
x -> post to wall

14. exercise write the magic-8 ball on shake,
use math->random to get a random number (say ‘x’)
use if statements to pick a predefined answer based on ‘x’ (you need at least 4 different answers).

15. pseudo-code
var x := math->random(3) // x is a random number of value 0, 1 or 2 if x = 0 then // display a message “this is looking good”->post to wall else // deal with x = 1, or x = 2 if x = 1 then “no way”->post to wall …

16. homework design your magic-8-ball game 6 different possible answers
1 option should draw a turtle shape
1 option should change the phone color
3 options should provide a picture
1 ‘customization’ of your own (make it fun, this is your app!)

17. reference
For reference, these are answers from the original game. ● It is certain● It is decidedly so● Without a doubt● Yes – definitely● You may rely on it● As I see it, yes● Most likely● Outlook good● Signs point to yes● Yes ● Reply hazy, try again● Ask again later● Better not tell you now● Cannot predict now● Concentrate and ask again ● Don't count on it● My reply is no● My sources say no● Outlook not so good● Very doubtful

18. if then else
choice, part iii

19. exercise
Write a script that prints the numbers 1 to 10 to the wall, skipping 4.
There are two good ways of doing this, but both use for loops. Once you have one, see if you can find the other.

20. question var x := math -> random (3) if x = 0 or x = 2 then
What does this do?
var x := math -> random (3)
if x = 0 or x = 2 then
1 -> post to wall
else
x -> post to wall

21. practice for 0 ≤ i < 4 do var x := i * 3 if x > 5 then else
x → post to wall
else
i → post to wall
var x := 3
if x = 2 then
“Yes” → post to wall
else
“No” → post to wall
if x > 2 then

22. if statements
choice, part vi

23. homework publish your script to get the script id log in
open homework script
tap on the “up button”, “publish”
wait still synching is finishing
mark id and return paper

24. if – then – else What will this code do? var x := 5 if x < 4 then
“purple” -> post to wall
else
“white” -> post to wall

25. if – then – else What will this code do? var x := 3 if x ≤ 4 then else
“brown” -> post to wall
else
“red” -> post to wall

26. practice var x := 1 var x := 3 var y := 3 if x > 2 then
if x > y then
“green” → post to wall
else
“black” → post to wall
“white” → post to wall
var x := 3
if x > 2 then
“pink” → post to wall
else
“orange” → post to wall

27. if – then – else var x := 3 if x < 7 then else x → post to wall
x := x * 2
else
x := x – 5
x → post to wall

28. practice var x := 0 var x := 6 var y := 3 if x = 2 then
x → post to wall
else
y → post to wall
var x := 6
if x = 2 then
x := 4
else
x := x + 2
x → post to wall

29. quiz

30. guessing game Pick a number between 1 and 20
Get someone to guess your number
Tell them whether they’re right, too high, or too low
Guess until they get the right answer
Think about how a computer would have to do this

31. user input The first step is to take user input
There’s an option on your phone called
wall → ask number
It returns the number given by the user (store it in a variable!)

32. guessing Have your phone pick a random number, then ask for a guess.
Tell the user whether they guessed right or wrong

33. guessing
The next step is to tell the user whether they guessed too high or too low.

34. guessing
One guess probably won’t be enough, so try to give the user two guesses
There’s more than one way to do this

35. guessing
Two probably still isn’t enough, so see if you can use a for loop to give the user even more guesses

36. challenge
If you have everything else working, see if you can figure out how to give the user an unlimited number of guesses

37. if statements
choice, part v

38. guessing game Pick a number between 1 and 20
Get someone to guess your number
Tell them whether they’re right, too high, or too low

39. guessing game
action guesser // pick a number between 0 and 20 var secret := math->random(21) // get someone to guess your number var guess := wall->ask number(“Guess”…) // Tell them too low if guess < secret then “too low”->post to wall else // Tell them whether too high if guess > secret then “too high”->post to wall // Tell them whether they’re right “you win!”->post to wall

40. math game
write a game where the user has to calculate the sum of 2 numbers

41. fill the holes /iiyh action math game
// get a random number and store it in ‘x’
// get a random number and store it in ‘y’
// ask the user for sum of both numbers // and store his number in ‘answer’
// check whether the answer is correct
if then // show the victory message |
else
// show the failure message |