Floating point unit facts for kids

A floating point unit (FPU) is a special part inside a computer that helps it do math with very specific kinds of numbers. These numbers are called floating point numbers. Think of them as numbers that can have a decimal point, like 3.14 or 0.0005, or even very large numbers like 6.022 x 10²³.

The FPU is designed to quickly perform math operations on these numbers. Common tasks it handles include addition, subtraction, multiplication, division, and finding the square root.

In most modern computers, you'll find one or more FPUs built right into the main brain of the computer, which is called the CPU. However, some smaller or older computer systems, especially those used in embedded devices like simple microcontrollers, might not have a special FPU at all.

What Does an FPU Do?

An FPU is like a super-fast calculator for numbers that aren't just whole numbers. Imagine you're doing complex science or engineering calculations; these often involve numbers with many decimal places or numbers that are extremely large or small. The FPU makes sure these calculations are done quickly and accurately.

While FPUs are great at basic math, some very advanced functions, like exponential or trigonometric functions (used in geometry and waves), are often handled by special computer programs called "software library routines" rather than directly by the FPU hardware. This is because it's more flexible to update these functions through software.

Where Are FPUs Found?

Most modern CPUs, which are the main processors in computers, have one or more FPUs built right inside them. This means the FPU is a core part of the CPU chip.

However, this wasn't always the case. In the past, some computers, like the old Intel 8086 system, used a separate chip called a coprocessor for floating point math. This coprocessor worked alongside the main CPU, helping it with the complex number crunching.

What Happens Without an FPU?

Not all computers have a dedicated FPU. If a computer doesn't have one, it can still do floating point math, but it has to do it differently. Instead of using special hardware, the computer uses software to "pretend" it has an FPU. This is called "emulation."

Emulation saves the cost of adding extra hardware, but it's much, much slower than having a real FPU. For tasks that need a lot of floating point calculations, like playing advanced video games or running scientific simulations, having a hardware FPU makes a huge difference in speed.

Related Computer Parts

• Arithmetic logic unit (ALU): This is another part of the CPU that handles basic math (like adding and subtracting whole numbers) and logical operations.
• Execution unit: This is a general term for a part of a CPU that performs operations. The FPU is a type of execution unit.

Images for kids

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  Collection of the x87 family of math coprocessors by Intel

See also

In Spanish: Unidad de coma flotante para niños