Students’ computation strategy preferences for multi-digit addition and subtraction problems using a free-choice format

This article describes the strategies of 71 students, ages 11-13, to multi-digit addition and subtraction problems using a free-choice format. Students were given the opportunity to solve each task two ways. Results showed that the majority of students converted the equation form of the task to a column method as their first preference. The column method incorporated standard algorithm strategies starting with the ones place and regrouping to higher place values to calculate the value of the unknown. On one of the three tasks, more than half of the students switched to a relational thinking strategy to find the unknown as their second-choice strategy. Less than half of the students used number relationships or equivalence strategies on the other two, more complex tasks for either of the two preferences. The overall preference for column methods as the first strategy choice was consistent across all three tasks.