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Sets

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visibility 55update a month agobookmarkshare

🎯 In this topic you will

Sort and count objects into sets
Use the words group and set correctly
Understand simple data

🧠 Key Words

data
group
set
sort

Show Definitions

data: Information that is collected and used to answer questions or show results.
group: A collection of objects that are put together because they share something in common.
set: A clearly defined collection of objects or items considered as one whole.
sort: To arrange objects into groups based on their similarities or differences.

🔍 Sorting into Sets

We need to know about organising into sets so that we can sort objects into which things belong together and which do not.

🧠 Looking for What Is the Same

When we sort, we look for something that is the same.

📘 Worked example

Here is a group of children. Sort them into two sets.

Answer:

Some of the children are girls.
We label the circle girls.
All the girls belong in this circle.

Some of the children are boys.
We label the circle boys.
All the boys belong in this circle.

We look for a clear property to sort the children.

Gender is used here, so one set contains all the girls and the other set contains all the boys.

Every child must go into exactly one correct circle so the sets are complete and do not overlap.

❓ EXERCISES

1. Sort these animals into the $2$ sets by writing the letters in the correct circle.

How many animals have stripes? $\square$

How many animals do not have stripes? $\square$

Tick the set that has more animals.

👀 Show answer

Stripes: $\text{A, G, H, I}$ → $4$ animals.
Not stripes: $\text{B, C, D, E, F}$ → $5$ animals.
The set with more animals is not stripes.

2. Sort these vegetables into the $2$ sets by writing the letters in the correct circle.

How many are red? $\square$

How many are not red? $\square$

Tick the set that has less.

👀 Show answer

Red: $\text{B, C, E}$ → $3$ vegetables.
Not red: $\text{A, D, F, G}$ → $4$ vegetables.
The set that has less is red.

🧠 Think like a Mathematician

Task: Find $2$ different ways to sort the houses. Show $1$ way in your book.

Method:

Look carefully at the houses labelled $A$ to $F$.
Find a property that can divide the houses into $2$ clear groups (for example, roof colour or number of windows).
Write the letters of the houses in the correct circles.
Think of another different way the houses could be sorted.

Follow-up Questions:

1. One possible sorting rule is by roof colour. Which houses have dark roofs and which have red roofs?

2. Give another property that could be used to sort the houses.

👀 show answer

1: Dark roofs: $A, B, C$. Red roofs: $D, E, F$.
2: Another valid sorting rule could be number of windows, door colour, or house height (for example, taller vs shorter houses).

📘 What we've learned

We learned how to sort objects into different sets using a clear rule.
We practiced identifying properties (such as stripes, colour, or type) to group items correctly.
We learned how to count the number of objects in each set and compare which set has more or less.
We used the mathematical language of $\text{group}$ and $\text{set}$ to describe collections of objects.