Inhibitory control and decimal number comparison in school-aged children

Area of Science:

• Cognitive Psychology
• Mathematics Education
• Developmental Psychology

Background:

• School-aged children frequently struggle with decimal number magnitude comparisons.
• A common error stems from applying whole number intuition (more digits = larger value) to decimals.
• This misconception is particularly evident when comparing decimals with differing numbers of digits (e.g., 1.45 vs. 1.5).

Purpose of the Study:

• To investigate the cognitive processes underlying decimal magnitude comparison in children.
• To determine if inhibiting the 'more digits, greater value' misconception is crucial for accurate decimal comparison.
• To explore the role of inhibiting decimal length perception in this comparison ability.

Main Methods:

• Utilized a negative priming paradigm with 7th-grade students.
• Experiment 1 involved comparing decimal numbers with varying and equal numbers of decimal places.
• Experiment 2 examined priming effects when decimal comparison preceded line length comparison tasks.

Main Results:

• A significant negative priming effect was observed when comparing decimals with differing numbers of digits.
• Participants showed slower response times after encountering decimals where the smaller number had more digits (e.g., 1.45 vs. 1.5).
• Negative priming also occurred when decimal comparison preceded a line length comparison task.

Conclusions:

• Accurate decimal magnitude comparison relies on inhibiting the intuitive 'more digits, greater value' rule.
• The ability to suppress the misconception derived from whole number properties is essential.
• Inhibiting the perception of decimal length itself also contributes to accurate comparison.