Basic Arithmetic and Numerical Reasoning
Numerical items mirror the arithmetic a correction officer performs on shift: reconciling counts, computing time, comparing quantities, and working with percentages. The math is simple; the errors come from misreading what is being counted and from unit mistakes.
Core operations
- Count reconciliation: start with the roster, subtract every inmate who is elsewhere, and compare with the number physically present. Any mismatch means recount and notify.
- Percentage: part divided by whole, multiplied by 100. Twelve of sixty is 0.20, or 20 percent.
- Time: use a 24-hour clock. From 22:45 to 06:15 is 7 hours 30 minutes, not 8 hours.
- Proportional reasoning: if a rate is given per unit or per shift, scale it to the quantity asked.
- Averages: total divided by number of items, useful for comparing overtime or population trends.
Worked example
A housing unit roster lists 48 inmates. At the 11 p.m. count, 4 are in the infirmary, 2 are at court, and 1 is in special housing. Expected present equals 48 minus 7, which is 41. If you count 40, you have a discrepancy of one and must recount and notify the supervisor before recording. Recording 41 without a recount is the wrong choice even though 41 is the expected number.
Traps
Including or excluding people who are already accounted for elsewhere. Sign errors when subtracting a group from a roster. Mixing hours and minutes. Rounding before the final step. Reporting a count as correct without resolving a mismatch.