Subtraction by addition in young multi-digit subtraction learners: A choice/no-choice study

Area of Science:

• Cognitive psychology
• Mathematics education
• Child development

Background:

• Children use direct subtraction (DS) or subtraction by addition (SBA) for subtraction problems.
• The use and adaptiveness of these strategies in young learners are not fully understood.

Purpose of the Study:

• To investigate third-graders' use of DS and SBA strategies.
• To examine strategy adaptiveness based on problem type and individual differences.
• To provide evidence for introducing SBA in early elementary education.

Main Methods:

• Employed a choice/no-choice method with 66 third-graders.
• Assessed performance on small and large difference subtraction problems.
• Analyzed strategy selection, accuracy, and speed.

Main Results:

• Nearly half of the children used SBA in the choice condition, despite only being taught DS.
• SBA was used for 20% of subtractions, with accuracy comparable to DS.
• One in five children made adaptive strategy choices, showing adaptability to strategy speed.

Conclusions:

• Third-graders demonstrate nascent use of the SBA strategy.
• SBA shows comparable accuracy to DS and can be used adaptively.
• The findings support the inclusion of SBA as an alternative strategy in early elementary math curricula.