Headwind or tailwind and crosswind (left or right) from wind direction and speed against a runway number or heading, with gusts.

Density altitude from field elevation, altimeter setting and temperature, exact and by rule of thumb, with a performance flag.

E6B arithmetic: give any two of distance, groundspeed and time for the third, plus fuel burn, reserve and range.

Glide distance, time and sink rate from altitude above ground, glide ratio and best-glide speed, with headwind or tailwind.

Standard atmosphere at an altitude: temperature, pressure, density, sound speed, and ISA deviation for a measured temperature.

Pressure altitude from field elevation and altimeter setting (inHg or hPa), exact ISA result and the 1000 ft per inHg rule.

True airspeed, Mach and equivalent airspeed from calibrated airspeed, pressure altitude and outside air temperature.

Identify a file type from the first bytes (hex): PNG, JPEG, PDF, ZIP, ELF, EXE, MP4, SQLite and 40+ more signatures.

Read a JPEG's width, height, components and baseline/progressive mode by walking its markers; flags JFIF and Exif.

Parse a gzip header: method, flags, modification time, original file name, OS and compression hint.

Read a GIF's version, width, height and global colour table size from its first 13 bytes.

Turn rate, radius, bank angle and load factor from true airspeed, plus holding pattern leg length, width and time.

Read a PDF's version and header position from its first bytes; flags junk before %PDF- and an invalid version.

E6B wind triangle: wind correction angle, heading and groundspeed for a course, or track and groundspeed for a heading flown.

Compare a file name's extension with its real type from the first bytes; flags executables disguised as documents or images.

Monthly saving needed to reach a goal by a date, given what you already have and an expected annual return.

Estimate a monthly electricity bill from kWh with block-tier rates, a fixed monthly charge and a tax or fee percentage.

Heat loss of a building in BTU/h and watts from surface areas and R-values plus air leakage, and yearly energy from degree-days.

Years to double money at a growth rate (exact and by the rule of 72), and how long inflation takes to halve buying power.

Return on investment and compound annual growth rate (CAGR) from a start value, end value and years held.