What term refers to the ability to understand numbers and their relationships?

• A. Number sense
• B. Data analysis
• C. Algebraic thinking
• D. Estimation

Answer: (A)

Number sense is the ability to understand numbers and how they relate to each other. It means having a feel for what numbers represent, how they compare (which is bigger or smaller), and how combining or separating numbers changes value. This includes recognizing quantity, using place value, decomposing numbers, and performing quick mental math or checking reasonableness of answers. It’s the flexible foundation that supports everyday math reasoning, number comparisons, and deciding efficient strategies. The other terms describe different skills: data analysis is about interpreting information from data sets; algebraic thinking involves recognizing patterns and solving equations with variables; estimation focuses on making reasonable, approximate calculations.