Foundations of Mathematical Thinking · Junior Infants · Data Analysis and Probability · Summer Term

Introduction to Probability: Likelihood of Events

Students will understand the concept of probability, describe the likelihood of events using terms like impossible, unlikely, equally likely, likely, and certain.

• NCCA Curriculum Specifications
• NCCA: Junior Cycle - Strand 3: Statistics and Probability - P.1.1

About This Topic

Young learners start probability by naming how likely events are with simple words: impossible, unlikely, equally likely, likely, certain. They spot impossible events like pigs flying or certain ones such as the sun rising daily. Everyday examples from games, weather, and stories help them tell equally likely outcomes apart, like heads or tails on a coin flip, from unlikely ones like drawing a red marble from a blue-heavy bag.

This topic fits NCCA's Foundations of Mathematical Thinking in Data Analysis and Probability. It builds early reasoning, language for chance, and prediction skills that support later number-based probability. Students answer key questions by making examples, sorting events, and discussing fairness in play, which strengthens observation and communication.

Active learning works well for this topic because abstract ideas come alive through play. Children test predictions with spinners, bags of objects, or weather charts, repeating trials to see chance in action. Shared excitement from group games cements vocabulary and turns uncertainty into a joyful discovery.

Key Questions

1. Differentiate between impossible and certain events.
2. Explain how to determine if an event is equally likely to occur or not occur.
3. Construct an example of an event that is unlikely but not impossible.

Learning Objectives

• Classify given events as impossible, unlikely, equally likely, likely, or certain.
• Explain the reasoning used to determine if an event is impossible or certain.
• Compare the likelihood of two different events using appropriate vocabulary.
• Construct an example of an event that is unlikely but not impossible.

Before You Start

Sorting and Classifying Objects

Why: Students need to be able to group items based on shared characteristics to understand how to categorize events by their likelihood.

Identifying Simple Patterns

Why: Recognizing patterns helps students anticipate outcomes, a foundational skill for predicting the likelihood of events.

Key Vocabulary

Impossible	An event that cannot happen under any circumstances.
Unlikely	An event that has a small chance of happening.
Equally Likely	An event where two or more outcomes have the same chance of happening.
Likely	An event that has a good chance of happening.
Certain	An event that is guaranteed to happen.

Watch Out for These Misconceptions

Common Misconception

Unlikely events can never happen.

What to Teach Instead

Children often see unlikely as impossible after one failed try. Hands-on bag pulls with rare items show these events occur sometimes over many trials. Group talks help them revise ideas with evidence from shared data.

Common Misconception

All game outcomes are equally likely.

What to Teach Instead

Young players assume fairness in every toy or game. Spinner activities reveal unequal sections lead to likely results. Discussing tallies in pairs builds understanding that equal chance needs balance.

Common Misconception

Certain events might not happen.

What to Teach Instead

Events like school starting confuse as certain if delayed once. Daily routines paired with sorting cards clarify always-happens traits. Whole-class prediction games reinforce through repetition and peer examples.

Active Learning Ideas

Sorting Game: Event Cards

Prepare picture cards showing events like 'it rains sweets' or 'the bell rings at break'. In small groups, children sort cards into five boxes labeled impossible, unlikely, equally likely, likely, certain. Groups share one example from each box with the class.

25 min·Small Groups

Bag Pulls: Color Chance

Fill bags with 10-20 colored pompoms, varying ratios like mostly blue for unlikely red. Pairs take turns predicting and pulling three times, recording with tallies or drawings. Discuss why some colors came up more.

30 min·Pairs

Spinner Trials: Prediction Wheel

Make large spinners with unequal sections for colors or faces. Whole class predicts likelihood before spinning 10 times as a group. Tally results on a chart and classify the spinner's outcomes together.

35 min·Whole Class

Weather Chat: Daily Odds

Each morning, individuals draw weather pictures and label likelihood for rain or sun based on forecasts. Share in circle time, adjusting labels after observing the day. Track over a week on a class poster.

20 min·Individual

Real-World Connections

• Weather forecasters use probability to describe the chance of rain, snow, or sunshine, helping people plan their day. For example, a forecast might say there is a 'likely' chance of rain, meaning it is probable.
• Game designers consider probability when creating board games or card games to ensure fairness. For instance, rolling a specific number on a fair die is 'equally likely' as rolling any other number.
• Manufacturers use probability to assess the likelihood of defects in products. A company might state it is 'unlikely' to find a faulty item in a batch, indicating a low probability of error.

Assessment Ideas

Exit Ticket

Provide students with a card listing 3-4 events (e.g., 'A cat will bark', 'The sun will rise tomorrow', 'You will eat an apple today'). Ask students to write one word (impossible, unlikely, equally likely, likely, certain) next to each event to describe its likelihood and draw a smiley face if it is certain or a neutral face if it is impossible.

Discussion Prompt

Present students with two scenarios: Scenario A: 'Flipping a coin and getting heads.' Scenario B: 'Picking a blue marble from a bag with 9 red marbles and 1 blue marble.' Ask: 'Which event is more likely to happen? Explain why you think so, using the words likely, unlikely, or equally likely.'

Quick Check

Hold up a set of picture cards showing different events (e.g., a pig flying, a child sleeping, a birthday cake). Ask students to give a thumbs up if the event is certain, thumbs down if it is impossible, and a thumbs sideways if it is likely or unlikely. Call on a few students to explain their choice.

Frequently Asked Questions

How do I introduce probability terms to Junior Infants?

Use picture sorts and stories with clear examples: impossible like flying elephants, certain like breathing. Start with whole-class modeling, then pairs practice labeling. Repeat in daily routines like snack time chances to build familiarity without pressure.

What active learning activities work best for probability in Junior Infants?

Games like bag pulls, spinners, and weather predictions engage senses and movement. Children predict, test, tally in groups, seeing chance patterns emerge. These build vocabulary through play, with 20-30 minute sessions keeping energy high and concepts memorable via trial and error.

What are common probability misconceptions for young children?

Pupils mix unlikely with impossible or assume all games are fair. Sorting cards and repeated spinner trials counter this by showing rare events happen and unequal setups skew results. Peer discussions after activities help correct views with class evidence.

How does this topic link to NCCA standards?

It matches Strand 3: Statistics and Probability P.1.1, focusing on describing likelihood qualitatively. Key questions on impossible, certain, and equally likely events develop early data skills. Hands-on work prepares for Junior Cycle by fostering prediction and reasoning foundations.