Achi is a strategy game from Ghana and is a more advanced form of noughts and crosses. Players take turns putting their markers on a 3x3 board, with the aim of trying to get three in a row. While playing, students will be required (unconsciously) to collect data and make predictions based on probability, to develop their own strategy for winning.
These reflective strategies (“If I do this, then they will do that.”) develop Mathematical thinking and problem solving.
Engage your students in a discussion using questions like:
Uses objects, diagrams and technology to explore mathematical problems
Describes mathematical situations and methods using everyday and some mathematical language, actions, materials, diagrams and symbols
Supports conclusions by explaining or demonstrating how answers were obtained
Recognises and describes the element of chance in everyday events
Describes and compares chance events in social and experimental contexts
Checks the accuracy of a statement and explains the reasoning used
Uses appropriate terminology to describe, and symbols to represent, mathematical ideas
Gathers and organises data, displays data in lists, tables and picture graphs, and interprets the results
Recognises and describes the element of chance in everyday events
Gathers and organises data, displays data in lists, tables and picture graphs
Reasons about representations of data to describe and interpret the results
Records and compares the results of chance experiments
Choose simple questions and gather responses
Identify a question of interest based on one categorical variable. Gather data relevant to the question
Collect, check and classify data
Conduct chance experiments, identify and describe possible outcomes and recognise variation in results
Identify practical activities and everyday events that involve chance. Describe outcomes as ‘likely’ or ‘unlikely’ and identify some events as ‘certain’ or ‘impossible’
Identify outcomes of familiar events involving chance and describe them using everyday language such as ‘will happen’, ‘won’t happen’ or ‘might happen’
Describe possible everyday events and order their chances of occurring
Identify everyday events where one cannot happen if the other happens
Identify events where the chance of one will not be affected by the occurrence of the other
Acquire data for categorical variables through surveys, observation, experiment and using digital tools; sort data into relevant categories and display data using lists and tables
Acquire and record data for categorical variables in various ways including using digital tools, objects, images, drawings, lists, tally marks and symbols
Conduct repeated chance experiments; identify and describe possible outcomes, record the results, recognise and discuss the variation
Identify practical activities and everyday events involving chance; describe possible outcomes and events as ‘likely’ or ‘unlikely’ and identify some events as ‘certain’ or ‘impossible’ explaining reasoning
Describe possible everyday events and the possible outcomes of chance experiments and order outcomes or events based on their likelihood of occurring; identify independent or dependent events
Identify outcomes of familiar events involving Probability (Chance) and describe them using everyday language such as ‘will happen’, ‘won’t happen’ or ‘might happen’
Choose simple questions and gather responses and make simple inferences
Identify practical activities and everyday events that involve Probability (Chance). Describe outcomes as ‘likely’ or ‘unlikely’ and identify some events as ‘certain’ or ‘impossible’
Identify a question of interest based on one categorical variable. Gather data relevant to the question
Conduct Probability (Chance) experiments, identify and describe possible outcomes and recognise variation in results
Identify everyday events where one cannot happen if the other happens
Have students begin by playing noughts and crosses and talking through different strategies for that game, before introducing Achi.
Instead of four pieces for each player, you can reduce the number of markers to three, making a game known as ‘Three Men’s Morris’ or ‘Nine Holes’.