**Description**Edit

*Back to Binary Calculator - Main Page*

This circuit is more complicated than subtractor and adder. Binary multiplier (as you can guess from its name) can multiply two binary numbers.

You can have some problems when you will try to build and use a multiplier -

- Unlike adder and subtractor (whitch have full and half version), this circuit has only half version (although it's not called half here). That means you can't connect the same circuits in series to make the final circuit have more bits. If you want to make this circuit have more bits, you'll have to completely rebuild it.
- Multipliers are using binary code, so it can be confusing to work with them. Binary code uses just 0 and 1, so you can write a number in binary using just switches (ON=1, OFF=0).
- Binary code uses bits (you can image a bit as a place reserved for 0 or 1).

If you want to build up one for yourself, you can look at this scheme of **2 bits times 2 bits** multiplier -

**A0** and **A1** stand for input of first factor - 2 bits, **B0** and **B1** stand for input of second factor - 2 bits, **C0-C4** stand for output - 4 bits

Or you can download this world file and test it yourself - Binary Calculator world file

**Tutorial for our world**Edit

The multiplier is on the left side and it's labeled, so it won't be problem to find it.

If you want to use it, don't forget these things -

- The multiplier has two groups of switches. The first group (left from X) represents first factor and the second group (right from X) represents second factor. Like on this picture -
- Our multiplier has just 2x2 bits, so these are all combinations of numbers you can count - 1x1,1x2,1x3,2x2,2x3,3x3
- It multiplies in real time, so please don't let the diodes interrupt you. You should look at them after finishing writing the numbers.