Read the markings
A resistor tells you its value in coloured bands, a ceramic capacitor in a three-digit code, and a part with a way round tells you in a stripe, a flat or a band. Each is a small piece of arithmetic or a thing to look for.
A resistor is a number in colour
Bands, read from the end nearest a band. On a four-band part the first two are digits, the third is how many zeros follow, and the fourth, set apart, is the tolerance. A five-band part has three digits. Black is 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8 and white 9. Gold and silver as a multiplier mean divide by ten and by a hundred.
Turn the dials. Set yellow, violet and red: that is 4 and 7 and two zeros, 4 700 Ω, which a person says as 4.7 kΩ.
The kit's resistors come in six values: 100 Ω, 220 Ω, 1 kΩ, 4.7 kΩ, 10 kΩ and 1 MΩ. Here is each, as both four and five bands. The store listing does not say which the box holds, so count the bands on yours and read the matching row.
Four of the six start with brown and black, so the first two bands say nothing and the third carries the whole difference. Read it slowly, or measure.
A capacitor is a number in a code
A ceramic capacitor, the small orange disc, prints its value as three digits: the first two are digits and the third is how many zeros to put after them, all in picofarads. So 104 is 10 followed by four zeros, which is 100 000 pF, which is 100 nF. A capacitor with only two digits, such as 22, is already in picofarads.
An electrolytic capacitor is bigger and prints its value in full, such as 100µF, with its voltage rating beside it. The rating is a limit: stay under it.
Which way round
A resistor and a ceramic capacitor have no way round. The parts that do each carry a mark, and it is a different mark on each.
Use the transistor drawing carefully. The order of its three legs is only usual: for both the S8050 and the 2N7000, one manufacturer's sheet reverses it. The print on the flat face says which part you have, and a meter, as the next article shows, says which leg is which.
When it does not work
Do not guess: measure. Put the meter in ohms range across the two wires and compare the reading with the bands. A resistor within its tolerance reads close to the colour-code value, and the band you were unsure of is then the one that fits.
Find the tolerance band, which stands apart from the others and is usually gold or silver, and put it on the right. If there is no gold or silver band, the end with the bands closest to it is the left. The meter settles it in one touch.
Within the tolerance, that is normal: a 5% part marked 4.7 kΩ may read anywhere from 4.47 to 4.93 kΩ. Outside it, either the resistor is not the one you think it is, it is still in a circuit, or your fingers are touching both probes and adding their own path.
Two digits with nothing after are the value in picofarads. Three digits are two digits and a count of zeros. Anything with a letter after it, such as 104K, is the same code followed by a tolerance letter, which you can ignore here.
Look at the rim of the dome: the flat cut is on the cathode side. Inside the dome the cathode has the bigger metal flag. Or use the meter's diode range: the red probe on the anode makes the LED glow faintly and show a number.
When the bands are worn off or the print has gone, the meter can say what a part is.
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