Source: https://mokxi.com/learn/path/electronics-math Updated: 2026-11-11 All paths # Math for electronics Metric prefixes, scientific notation, Ohm's law rearranged, ratios and tolerance, watts and squares, RMS and decibels: every answer set on a real part and proved on a meter, ending in a component calculator. Free 8 lessons 6 h 5 chapters 1,950 XP Electrical ยท Beginner +100 XP 0 of 8 done Start the course free Kilo, milli, micro and mega Lesson plan for teachers What you will build ## 3 projects, built step by step 8 lessons in 5 chapters, about 6 hours on a simulated breadboard. Free, in your browser, every step checked by the simulator. Chapter 1 project ### Scientific notation A 12 V supply into one resistor: write currents as 1.2e-2 and 2.55e-6, multiply and divide by adding exponents, and check every answer against the resistor's own reading. Open it in the simulator Chapter 2 project ### Ratios, percent and tolerance A divider is a ratio machine: make a tap at half, at 20 percent, then knock two resistors 5 percent high and work out how far the output moves. Open it in the simulator Chapter 3 project ### Square roots and RMS A function generator into a load, a scope for the peak and a meter for the RMS: why 1.414 shows up everywhere in AC, and why a square wave and a triangle break the rule. Open it in the simulator The map ## Chapter by chapter Each lesson opens when the one before it is done, and each chapter ends in a project. Chapter 1 ## Big and small numbers Kilo, milli and micro, and numbers with an exponent. Open 175 XP ### Kilo, milli, micro and mega Three resistors from 5 V to ground and a meter on the bottom one: read kilohms, milliamps and microamps off real parts, and move between prefixes without a calculator. 0 of 6 steps Start What is in it Project Locked 350 XP ### Scientific notation A 12 V supply into one resistor: write currents as 1.2e-2 and 2.55e-6, multiply and divide by adding exponents, and check every answer against the resistor's own reading. 0 of 6 steps Chapter 2 ## Ohm's law and ratios Solve for any letter, and make a divider hit a percent. Locked 175 XP ### Ohm's law, three ways round Solve V = I x R for whichever letter is missing: find a current, pick a resistor for a current you want, pick a voltage, and read a current limit as Ohm's law in disguise. 0 of 6 steps Project Locked 350 XP ### Ratios, percent and tolerance A divider is a ratio machine: make a tap at half, at 20 percent, then knock two resistors 5 percent high and work out how far the output moves. 0 of 6 steps Chapter 3 ## Powers and roots Watts and squares, and the square roots inside AC. Locked 175 XP ### Watts, squares and power ratings P = V x I, then P = I squared x R and V squared over R: why half the volts is a quarter of the heat, and how to pick a resistor that will not cook. 0 of 6 steps Project Locked 350 XP ### Square roots and RMS A function generator into a load, a scope for the peak and a meter for the RMS: why 1.414 shows up everywhere in AC, and why a square wave and a triangle break the rule. 0 of 6 steps Chapter 4 ## Decibels Logs that turn ratios into numbers you can add. Locked 175 XP ### Decibels and logs An RC low pass on a function generator: find the -3 dB point, see -20 dB a decade above it, and turn voltage ratios into decibels and back with a log. 0 of 6 steps Chapter 5 ## Boss project A component calculator that you redo for a new supply. Locked 200 XP ### Boss: the component calculator One bench supply, three jobs: pick an LED resistor for 20 mA, a divider for 3.3 V and a load resistor's power rating, then swap the supply to 12 V and do it all again. 0 of 7 steps Syllabus ## Every lesson in the course All 8 lessons, in order, each with what it covers. Any of them opens in the editor right away. Chapter 1 ### Big and small numbers - Kilo, milli, micro and mega Three resistors from 5 V to ground and a meter on the bottom one: read kilohms, milliamps and microamps off real parts, and move between prefixes without a calculator. - Scientific notation A 12 V supply into one resistor: write currents as 1.2e-2 and 2.55e-6, multiply and divide by adding exponents, and check every answer against the resistor's own reading. Chapter 2 ### Ohm's law and ratios - Ohm's law, three ways round Solve V = I x R for whichever letter is missing: find a current, pick a resistor for a current you want, pick a voltage, and read a current limit as Ohm's law in disguise. - Ratios, percent and tolerance A divider is a ratio machine: make a tap at half, at 20 percent, then knock two resistors 5 percent high and work out how far the output moves. Chapter 3 ### Powers and roots - Watts, squares and power ratings P = V x I, then P = I squared x R and V squared over R: why half the volts is a quarter of the heat, and how to pick a resistor that will not cook. - Square roots and RMS A function generator into a load, a scope for the peak and a meter for the RMS: why 1.414 shows up everywhere in AC, and why a square wave and a triangle break the rule. Chapter 4 ### Decibels - Decibels and logs An RC low pass on a function generator: find the -3 dB point, see -20 dB a decade above it, and turn voltage ratios into decibels and back with a log. Chapter 5 ### Boss project - Boss: the component calculator One bench supply, three jobs: pick an LED resistor for 20 mA, a divider for 3.3 V and a load resistor's power rating, then swap the supply to 12 V and do it all again. Kits ## Build it on your bench too Every lesson runs in the simulator with nothing to buy. When you want the real thing, these kits have the parts. Have a kit already? ### Find your kit Pick the starter kit you own and run every lesson in its manual with the same parts on the same pins. See every kit Questions ## About Math for electronics Is Math for electronics free? Yes. All 8 lessons of Math for electronics are free and run in your browser, with nothing to install and no parts to buy before you start. Do I need any parts? No. Every circuit is built on a simulated breadboard, and the simulator checks each step as you go. When you want to build it for real, the same parts and wiring work on a real bench. How long does Math for electronics take? About 6 hours: 8 lessons in 5 chapters, each one a few short steps. Your progress is kept, so you can stop after any lesson and pick up where you left off. What will I build? Each chapter ends in a project that puts it together: Scientific notation, Ratios, percent and tolerance and Square roots and RMS. Where do I start? With "Kilo, milli, micro and mega", and each lesson builds on the one before it. New to circuits? Electronics basics is the course that starts from zero.