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  • Identify the variable to which that block applies by selecting the variable name in the pull-down list built into the block.
  • Enter a literal numeric or string value from the keyboard into the white or gray text field at the right end ofthe block, or
  • Drag some other block and drop it into the white or gray text field.

There are at least two different shapes that are eligible for being dropped into such text fields:

  1. A horizontal rectangle with rounded corners such as the orange block labeled Counter in Image 1 . (This shape seems to always be associated with a numeric or string value.)
  2. A horizontal rectangle with pointed ends as shown by several of the blocks in Image 4 . (This shape seems to always be associated with a boolean result of true or false.)

Blocks having the rounded corners are eligible for being dropped into the white text fields with rounded corners of the programming blocks in Image 1 .

Blocks having the pointed ends are eligible for being dropped into the darker orange text fields having a similar shape on the blocks that areexposed by clicking the Control button in the programming interface.

Either shape of block is eligible for being dropped into the white text fields withsquare corners shown in Image 1 . Thus the block in Image 1 that is used to set a variable to a value can set the value to a numeric value,a string value, or a boolean value.

(Note that the two variable blocks shown in Image 1 labeled Counter and counter are eligible for being dropped into the white text fields ofthe two programming blocks shown in Image 1 . This makes it possible to cause the value of one variable to depend on the valueof another variable.)

If you click the Operators button shown in Image 1 (see Image 4 ) you will expose several different blocks with rounded corners that are eligible for being dropped into thewhite text fields in Image 1 according to the rules described above.

Cause the variables to be displayed

As mentioned earlier, checking the boxes to the left of the variable names in Image 1 causes them to be displayed in the upper-left corner of the Stage shown in Image 1 . (Clicking the show and hide blocks will also check and uncheck the checkboxes, which in turn will show or hide the variables on the stage.)

Create a new variable

You create a new variable by clicking the button labeled Make a variable shown in Image 1 . When you click that button, the dialogshown in Image 2 appears on the screen asking you to provide the name for the new variable.

Image 2. dialog for entering a variable name.

Missing image
Image 2. Dialog for entering a variable name.

At that point, you simply type in the name for the new variable and click the OK button.

The radio buttons on that dialog allow you to specify which sprites have access to the variable.

The disabled cloud variable button (shown in light gray in Image 2 ) is a new feature of Scratch 2.0. Apparently registered users who are signed in can check that button and save the variable on the MITwebsite or on a website controlled by MIT. I wasn't signed in, which is why it was disabled.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket 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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