# 1.5 Scr0350: relational operators in scratch 2.0  (Page 4/6)

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## Where are the blocks with the correct shape?

There are two buttons (possibly more) that we can click in the upper left in Image 5 that will expose blocks with shapes matching the pocket immediately to the right of the word if in Image 5 :

• Sensing
• Operators

## Will use blocks from the Operators group

In this module, we will use three of the blocks that are exposed by clicking the green Operators button as shown in Image 6 .

## Six blocks have the correct shape

As you can see in Image 6 , there are six blocks of the correct shape exposed by clicking the Operators button. Those blocks are identified as follows:

```<(less than) = (equal to)>(greater than) andor not```

We will refer to the first three blocks above as relational operators . (They are used to evaluate the relationship between two values.) We will refer to the other three blocks in the above list as logical operators , and will deal with them in a future module.

## Relational operators in other languages

Many other modern programming languages also include the following three relational operators:

```>= (greater than or equal)<= (less than or equal) != (not equal)```

Although these operators are a great convenience, they are not essential. We can get by with only the three that are provided by Scratch.

Also, in many other programming languages, a pair of equal characters (==) is used for the "equal to" operator instead of the single equal character (=) used in Scratch.

## Three steps at once

Image 7 shows the result of three more steps in the development of the program:

1. Dragging the green less than (indicated by a left angle bracket) block and dropping it into the pocket immediately to the right of the word if .
2. Dragging the orange block labeled set...to for the variable named LessThan and inserting it immediately below the word if . I also set its literal value to "Less than is true".
3. Dragging another copy of the orange block labeled set...to for the variable named LessThan and inserting it immediately below the word else . I also set its literal value to "Less than is false".

## Still need to complete the conditional clause

The script in Image 7 includes the action to be taken if the relational expression following the word if evaluates to true. It also includes the action to be taken if therelational expression evaluates to false. (This relational expression is often referred to as a conditional clause.) .

However, we still haven't completed the conditional clause in Image 7 . We don't want to test for the relationship between the literal values blank and blank as shown in Image 7 . Instead we want to test the relationship between the values of the variablesnamed LeftOperand and RightOperand as shown in the corresponding script in Image 4 .

## Complete the relational expression

The next and final step for constructing this script is to:

where we get a research paper on Nano chemistry....?
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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