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Repetitively clicking the mouse in the Stage area causes the Counter variable to count down in increments of oneand causes the counter variable to count down in increments of five.

Event-driven programming

The ability to write programs that cause certain operations to occur in response to events (such as pressing the space bar and clicking the mouse on the Stage) is often referred to as event-driven programming.

It is easy to write event-driven programs in Scratch. On the other hand, writing event-driven programs is not so easy in languages such asJava, C#, and C++. You need quite a lot of programming knowledge to write event-driven programs in those languages.

It is useful to give programming students a taste of event-driven programming early, if for no other reason than the factthat it tends to make programming more interesting.

Example blocks with pointed ends

The blocks shown in Image 4 are not used in this program. They are shown in this module to illustrate blocks with pointed endsreferred to earlier .

Image 4. example blocks with pointed ends.

Missing image.
Image 4. Example blocks with pointed ends.

Run the program

I encourage you to use the information provided above along with the Scratch 2.0 programming interface shown in Image 1 to write and run this program. Experiment with the code, making changes, and observing the results of yourchanges. Make certain that you can explain why your changes behave as they do.

A copy of this program has been posted online for your review.

I also encourage you to write the programs described below.

Student programming projects

The following projects are designed to:

  • Help the student retain the knowledge gained by studying the module.
  • Require the student to think beyond the material presented in the module by requiring the student to answer the question "How do I ...?"

Project 1

Begin with the program named Variable01 and modify it to create a new program named Variable02 . Modify the original program in such a way that pressing the space bar five times in succession, (after clicking the green flag to set both variables to zero) , will cause the displayed values of the variables named Counter and counter to be as shown in Image 5 .

Image 5. output from project 1.

Missing image.
Image 5. Output from Project 1.

Having reached that point, clicking the mouse five times in succession in the Stage area will cause the displayed values of the variables named Counter and counter to be as shown in Image 6 .

Image 6. output from project 1.

missing image
Image 6. Output from Project 1.

A copy of this program is posted online for your review.

Project 2

You should successfully complete Project 1 before attempting this project. Begin with the program named Variable01 and modify it to create a new program named Variable03 . Modify the original program in such a way that pressing the space bar five timesin succession, (after clicking the green flag to set both variables to zero) , will cause the displayed values of the variables named Counter and counter to be as shown in Image 7 .

Image 7. output from project 2.

Missing image.
Image 7. Output from Project 2.

Questions & Answers

what is math number
Tric Reply
x-2y+3z=-3 2x-y+z=7 -x+3y-z=6
Sidiki Reply
Need help solving this problem (2/7)^-2
Simone Reply
x+2y-z=7
Sidiki
what is the coefficient of -4×
Mehri Reply
-1
Shedrak
the operation * is x * y =x + y/ 1+(x × y) show if the operation is commutative if x × y is not equal to -1
Alfred Reply
An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?
Kala Reply
lim x to infinity e^1-e^-1/log(1+x)
given eccentricity and a point find the equiation
Moses Reply
12, 17, 22.... 25th term
Alexandra Reply
12, 17, 22.... 25th term
Akash
College algebra is really hard?
Shirleen Reply
Absolutely, for me. My problems with math started in First grade...involving a nun Sister Anastasia, bad vision, talking & getting expelled from Catholic school. When it comes to math I just can't focus and all I can hear is our family silverware banging and clanging on the pink Formica table.
Carole
I'm 13 and I understand it great
AJ
I am 1 year old but I can do it! 1+1=2 proof very hard for me though.
Atone
hi
Adu
Not really they are just easy concepts which can be understood if you have great basics. I am 14 I understood them easily.
Vedant
find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
salma
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
If f(x) = x-2 then, f(3) when 5f(x+1) 5((3-2)+1) 5(1+1) 5(2) 10
Augustine
how do they get the third part x = (32)5/4
kinnecy Reply
make 5/4 into a mixed number, make that a decimal, and then multiply 32 by the decimal 5/4 turns out to be
AJ
how
Sheref
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
I rally confuse this number And equations too I need exactly help
salma
But this is not salma it's Faiza live in lousvile Ky I garbage this so I am going collage with JCTC that the of the collage thank you my friends
salma
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
hi
salma
hi
Ayuba
Hello
opoku
hi
Ali
greetings from Iran
Ali
salut. from Algeria
Bach
hi
Nharnhar
A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
Kimberly Reply
Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
August Reply
What is the expressiin for seven less than four times the number of nickels
Leonardo Reply
How do i figure this problem out.
how do you translate this in Algebraic Expressions
linda Reply
why surface tension is zero at critical temperature
Shanjida
I think if critical temperature denote high temperature then a liquid stats boils that time the water stats to evaporate so some moles of h2o to up and due to high temp the bonding break they have low density so it can be a reason
s.
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
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Source:  OpenStax, Teaching beginners to code. OpenStax CNX. May 27, 2013 Download for free at http://cnx.org/content/col11498/1.20
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