Practise · about 2 minutes a round
Speed drills
Short rounds of quick questions on the things you need at your fingertips: colour codes, unit prefixes and Ohm’s law. Speed comes from practice, and practice sticks best in short, frequent bursts.
Drill
Type numbers with or without prefixes: 4.7k, 4700 and 4.7 k all mean 4 700. Answers within 2% count (colour codes must be exact). A calculator is fine.
Round over
Your best rounds
Kept in this browser only. Timed rounds count right answers; untimed rounds record your time for ten questions.
Prefer paper? Print a worksheet with an answer key.