
SILO 1.2 (DRAFT) Year 1, Term 2: Symbols Focus: Comparisons Scope and sequence: = < >
Learning intention: Students make comparisons and use symbols to describe relationships.
NSW Syllabus	Australian Curriculum (version 9.0)
"A student describes and compares the masses of objects." (MAE-NSM-01)	"Students learn to quantify and compare collections to at least 20 using counting and explain or demonstrate reasoning." (AC9MFN03)

Signs and symbols

When you’re driving along the road, you might notice that the signs include little or no words – this is because when a driver is travelling along the road, they have to understand the message that the sign is getting across at the glance of an eye!

Signs use icons and pictures to illustrate a message clearly. What you interpret from the icon is most likely what the sign means – there is not often a hidden meaning behind signs. Can you think of some common signs you have seen around?

Symbols, on the other hand, are often used to represent something. For example, when you go to a restaurant and look at a menu, you may see a leaf symbol next to some options, representing that they are suitable for vegetarians. Or an even more common symbol you have likely seen around is this one:

(Image source: https://commons.wikimedia.org/wiki/File:Recycling_symbol_blue.svg)

What do these three arrows represent? Can you think of some other common symbols you have seen around?

Activity
PART 1 – SIGNS
Today’s task is to use signs and symbols to illustrate the map below, and help Susie direct her aunt who will be driving her from her house to her school today.

Draw a path on the map that you are going to follow to reach your destination, and every sign that you come across on your route, you have to tell your aunt what it means!

PART 2 – SYMBOLS
For the second part of our activity today, we are going to play a game of class Pictionary, using different SYMBOLS as the prompts.

Students will come up to the whiteboard one at a time and choose a piece of paper containing a symbol on it. They will have to draw the symbol on the whiteboard, and the class will have to guess what the symbol means. The first student to guess correctly will get to be the next one to come up to the front and draw.

Introduction to codes

What is a code?

Morse code

Morse code is a method of communication to encode text characters as sequences of two different signal durations, called dots and dashes (or dits and dahs). Morse code is named after Samuel Morse although Joseph Henry and Alfred Vail were also involved. Morse code has been around since 1837.

(Image source https://en.wikipedia.org/wiki/Morse_code#/media/File:International_Morse_Code.svg)

The following video (2:00) shows how to make an electric circuit to use for Morse code.

The previous video showed how you can use a peg to make a switch. The following image is of a switch symbol. Notice how it is just a break in a circuit which can be easier closed by bringing the two parts together.

Coding a Micro:bit for Morse code

The code on the left will produce sound on a Micro:bit. Button A will play a dash and Button B will play a dot. Although Micro:bits are not very loud, in a classroom setting this activity can be quite noisy and students could struggle to hear clearly. For this reason the code on the right is recommended which uses lights instead. Although a dash normally means that a light is held for a longer duration, the code here has an actual dash comprised of three dots to make the communication easier to decipher.

Tip: It is recommended that students confirm each letter before moving onto the next one.

The Morse code key can also be printed as an A4 worksheet by clicking here.

Pig pen code

(Source: https://commons.wikimedia.org/w/index.php?curid=4219969)

Activity: Create your own variation on pig pen code. A double-sided A4 sheet for the pig pen code activity is available by clicking here.

Less than, greater than, equal to

The following video (2:50) explains and demonstrates some of the symbols which are used to compare quantities.

As the video mentions, we use symbols to illustrate the results of comparing two quantities. Wait – what is a QUANTITY?
Quantity is the amount of something that we are looking at. For example, if we have 6 cookies in a jar, 6 is the quantity of cookies that we have.
When we say something is GREATER THAN something else, we draw a crocodile shape pointing towards the bigger quantity to represent this.

We can remember this by representing the numbers we are comparing as something delicious the crocodile wants to eat – such as fish! Because fish are so delicious, the crocodile will want to eat the larger quantity, opening its mouth towards the bigger number!

We can read the above diagram in two ways:

9 is GREATER THAN 2
2 is LESS THAN 9.

The first phrase would be used if the first quantity is larger than the second, and the second phrase would be used if the second quantity is larger than the first. No matter which way you phrase this, the fact remains that 9 is the BIGGER QUANTITY and 2 is the SMALLER QUANTITY, and therefore the crocodile will always point with his mouth open to the 9, the larger number.

But what do we do if both choices represent the SAME quantity?

Does anyone have an idea of which way the crocodile should face?

In this case, because the numbers are equal to each other, we use a different type of symbol: an EQUAL SIGN, which illustrates that the two quantities are THE SAME.

Activity (Idea from https://jillianstarrteaching.com/greater-than-and-less-than-signs/)
For this activity, everyone is going to receive a worksheet, and your task is to compare the two quantities in each row and use the correct symbol to represent which number is GREATER or LESS than the other, or if both quantities are equal. The three symbols that you will be using are listed below, and you will write the appropriate one in the middle column of each row of the worksheet:

To accomplish this task, everyone will be given a handful of blocks and two popsicle sticks. You are going to stack the blocks into sets the size of each quantity listed in the row, and rest the popsicle sticks on the top and bottom of the stack to assist in the completion of the worksheet. For example, if you are comparing the quantity of 1 and 3, your block stacking might look like this:

Therefore, you can see that 1 < 3, or 1 is LESS THAN 3, since it looks like the crocodile has opened its mouth towards the three.

Place the correct symbol in the blank column below.
Hint: It will either be greater than (>), less than (<), or equal to (=).
This can also be printed as an A4 worksheet by clicking here.

Pseudocode

Pseudocode is a way to represent code using plain English and common symbols. A remote control for an air conditioner can be used as an introduction to programming. The following image shows that the air conditioner will heat the room until it reaches 23 degrees Celsius. Using pseudocode, this could be written as follows:

IF temperature < 23 degrees THEN ON

Binary code

Computer coding involves coding languages and, just like spoken language, there are many in use around the world. Computers and digital devices use binary code, where the two options are on and off. This is a little like when you used Morse code and there were just two options, dots and dashes. The on and off in binary code is commonly achieved using electrical pulses at 5 volts. The following image shows off as a black box and on as white. Each box is a 'binary digital' or bit. Eight bits together is a byte. As you can see below, each letter of our alphabet can be represented using eight bits.

Binary code chart

(Image source https://code.org/curriculum/course2/14/Teacher)

Binary bracelet activity

This binary bracelet activity involves giving each student a piece of paper with the following image.

Ask each student to colour in the boxes to represent the first letter of their name as shown in the binary code chart above.
The bracelet can then be attached to their wrist using tape, glue or a fastener such as a carefully placed staple.
A printable A4 sheet with 10 binary bracelets is available by clicking here.

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

SILO 1.2 (DRAFT)

Year 1, Term 2: Symbols

Focus: Comparisons Scope and sequence: = < >

Learning intention: Students make comparisons and use symbols to describe relationships.