Performing calculations in one's head without the use of paper or a calculator.

Performing calculations in one's head without the use of paper or a calculator.

• A. Estimation
• B. Abacus Work
• C. Mental Math
• D. Rapid Calculation

Answer: (C)

Mental math is performing calculations in your head without paper or a calculator. It uses strategies to break numbers into easier parts and keep a running total, aiming for an exact result rather than a rough guess. For example, adding 47 and 68 can be done as 47 + 68 = (40+60) + (7+8) = 100 + 15 = 115. This shows how you reorganize the problem to simplify computation in your head. Estimation would give a close answer rather than the exact sum. Abacus work involves a physical tool, not head-only calculation. Rapid calculation is a broad term that doesn’t specify it must be done mentally.

Mental math is performing calculations in your head without paper or a calculator. It uses strategies to break numbers into easier parts and keep a running total, aiming for an exact result rather than a rough guess. For example, adding 47 and 68 can be done as 47 + 68 = (40+60) + (7+8) = 100 + 15 = 115. This shows how you reorganize the problem to simplify computation in your head.

Estimation would give a close answer rather than the exact sum. Abacus work involves a physical tool, not head-only calculation. Rapid calculation is a broad term that doesn’t specify it must be done mentally.