Grade 1 
 discuss events using words such as ‘likely’, ‘unlikely’, ‘certain’, ‘impossible’.
 place the probability of events on a scale from impossible to certain.
 use the language of chance or likelihood
 find probabilities based on equally likely outcomes in simple contexts.
 List all outcomes for single events systematically

Grade 2 
 use the vocabulary and ideas of probability, drawing on experience
 understand and use the probability scale from 0 to 1
 find and justify probabilities based on equally likely outcomes in simple contexts
 identify all the possible mutually exclusive outcomes of a single event.
 Find the probability of an event happening using theoretical probability
 Use theoretical models to include outcomes using dice, spinners, coins
 Write probabilities in words or fractions, decimals and percentages
 Work out probabilities from frequency tables
 Identify different mutually exclusive outcomes and know that the sum of the probabilities of all outcomes is 1
 estimate probabilities by collecting data from a simple experiment and recording in a frequency table
 compare experimental and theoretical probabilities in simple contexts.
 Find the probability of an event happening using relative frequency
 Estimate the number of times an event will occur, given the probability and the number of trials – for both experimental and theoretical probabilities
 List all outcomes for combined events systematically

Grade 3 
 interpret results of an experiment using the language of probability and appreciate that random processes are unpredictable
 know that, if the probability of an event occurring is p, then the probability of it not occurring is 1 – p
 use diagrams and tables to record all possible mutually exclusive outcomes for single events and for two successive events
 Work out probabilities from twoway tables
 Record outcomes of probability experiments in tables
 Add simple probabilities
 List all outcomes for combined events systematically
 Use and draw sample space diagrams
 compare estimated experimental probabilities with theoretical probabilities, recognising that:
 if an experiment is repeated, the outcome may and usually will be different
 increasing the number of times an experiment is repeated generally leads to better estimates of probability
 Work out probabilities from Venn diagrams to represent reallife situations and also ‘abstract’ sets of numbers/values
 Compare experimental data and theoretical probabilities
 Use tree diagrams to calculate the probability of two independent events

Grade 4 

Grade 5 
 Write probabilities using fractions, percentages or decimals;
 Understand and use experimental and theoretical measures of probability, including relative frequency to include outcomes using dice, spinners, coins, etc;
 Estimate the number of times an event will occur, given the probability and the number of trials;
 Find the probability of successive events, such as several throws of a single dice;
 List all outcomes for single events, and combined events, systematically;
 Draw sample space diagrams and use them for adding simple probabilities;
 Know that the sum of the probabilities of all outcomes is 1;
 Use 1 – p as the probability of an event not occurring where p is the probability of the event occurring;
 Draw a probability tree diagram based on given information, and use this to find probability and expected number of outcome;
 Work out probabilities from Venn diagrams to represent reallife situations and also ‘abstract’ sets of numbers/values;
 Use union and intersection notation;

Grade 6 

Grade 7 

Grades 8  9 
