Multipliers are built using binary adders.

Explanation:
A multiplier is a digital circuit that performs the operation of multiplication. It takes two binary numbers as inputs and produces their product as the output. The process of multiplication involves adding the partial products obtained by multiplying the individual bits of the two numbers.

Binary Adders:
A binary adder is a digital circuit that performs the addition of two binary numbers. It takes two binary inputs and produces their sum as the output. Binary adders are fundamental building blocks in digital systems and are widely used in various applications.

Building a Multiplier:
To build a multiplier, we can use a combination of binary adders. The process involves multiplying each bit of one binary number (the multiplicand) with each bit of the other binary number (the multiplier), and then adding the partial products to obtain the final product.

The multiplication process can be divided into several steps:
1. Multiplication of each bit: Multiply each bit of the multiplicand with each bit of the multiplier. This can be done using simple AND gates.
2. Alignment of partial products: Align the partial products obtained in the previous step according to their respective positions.
3. Addition of partial products: Add the aligned partial products using binary adders.

Working of a Multiplier:
1. The multiplicand and multiplier are fed into the multiplier circuit.
2. The multiplier bits are examined one by one, starting from the least significant bit (LSB).
3. For each multiplier bit:
- If the bit is 0, the partial product is zero.
- If the bit is 1, the multiplicand is added to the partial product obtained so far.
4. The partial products are aligned and added together using binary adders to obtain the final product.

Advantages of using Binary Adders:
- Binary adders are simple and efficient circuits.
- They can be easily implemented using basic logic gates.
- They can handle binary numbers of any length.
- Binary adders can be cascaded to perform addition of larger numbers.

Therefore, binary adders are the preferred choice for building multipliers as they provide a straightforward and efficient way to perform the necessary addition operations in the multiplication process.