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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

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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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?
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
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit 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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