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Numeric keypad

Numeric keypad is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Numeric keypad rather than just read about it. In short: A numeric keypad, number pad, numpad, or ten key, is the calculator-style group of ten numeric keys accompanied by other keys, usually on the far right side of computer keyboard. This grouping allows quick number entry with the right hand, without the need to use both hands on number row of main keyboard.

Numeric keypad — main illustration
Numeric keypad — illustration

Key takeaways

  • Numeric keypad belongs to computer science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Numeric keypad to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Numeric keypad from memory before moving on to harder problems.

Reference excerpt

A numeric keypad, number pad, numpad, or ten key, is the calculator-style group of ten numeric keys accompanied by other keys, usually on the far right side of computer keyboard. This grouping allows quick number entry with the right hand, without the need to use both hands on number row of main keyboard. On a standard IBM PC keyboard, numpad has 17 keys, including digits 0 to 9, + (addition), - (subtraction), * (multiplication), and / (division) symbols, . (decimal point), Num Lock, and ⌅ Enter keys. On smaller keyboards (such as those found on laptops), the numeric keypad can be implemented as alternative markings on alphabetic keys (usually I-O-P, K-L-;, ,-.-/) or added as a separate unit, that can be connected to a device by means such as USB; some of these may include keys not found on a standard numpad, such as a spacebar or a 00 (or 000) key. Sometimes it is necessary to distinguish between a key on the numpad and an equivalent key elsewhere on the keyboard. For example, depending on the software in use, pressing the numpad's 0 key may produce different results than pressing the alphanumeric 0 key. In such cases, the numpad-specific key may be indicated as e.g. Numpad 0, NumPad0, Num 0, or likewise to remove ambiguity. Numeric keypads usually operate in two modes. When Num Lock is off, keys 8, 6, 2, and 4 act like the arrow/navigation keys up, right, down, and left; and 7, 9, 3, and 1 act like Home, PgUp, PgDn, and End, respectively. With Num Lock on, digit keys produce the corresponding digit. On Apple Macintosh computers, which lack a Num Lock key, the numeric keypad always produces only numbers; the Num Lock key is replaced by the Clear key. The arrangement of digits on numeric keypads with the 7-8-9 keys two rows above the 1-2-3 keys is derived from calculators and cash registers. It is notably different from the layout of telephone Touch-Tone keypads which have the 1-2-3 keys on top and 7-8-9 keys on the third row. Numeric keypads are useful for entering long sequences of numbers quickly, such as in spreadsheets, financial/accounting programs, and calculators. Input in this style is similar to a calculator or adding machine. Similarly to how the F and J keys on a QWERTY keyboard have raised bars or dots to aid finger placement for touch typists, the 5 key on a numeric keypad may have its own raised bar to assist in entering numbers and calculations by touch. Typically, the middle finger of the right hand will be placed on the 5 key, with the index finger on the 4 key and the ring finger on the 6 key. A numeric keypad is also useful on Windows PCs for typing alt codes for special symbols; for example, the degree symbol, °, can be typed on these computers by holding down Alt and typing 0176. To maintain their compact size, most laptops do not include a numeric keypad on their keyboard (though they can sometimes be found on larger models); even some desktop keyboards designed for compactness omit a numpad. To compensate, most such keyboards include Num Lock integrated into a function key (typically F6 or F8) and then press keys like 7 to produce their numpad counterpart.

Chinese input methods The numeric keypad is used by some systems for input of Chinese characters, for example CKC Chinese Input System and Q9 input method.

Computer games and mousing alternative

Numeric keypads are also used for playing some older computer games where the player must control a character, such as roguelikes and Sid Meier's Pirates!. For keyboards without a numeric keypad, some games provide alternative movement keys, such as classic Rogue's HJKL keys. The numeric keypad can also be an alternative to the WASD keys for navigation in computer gaming. This can be an attractive option for left-handed people who prefer to use the mouse with their left hand. Most operating systems have a mouse keys accessibility feature where mouse navigation can be done using the numeric keypad, with the other keys adapted to be mouse buttons.

See also Alphonse Chapanis Gaming keypad Keypad

Notes

References

Illustrations

Numeric keypad: Numeric keypad, integrated with keyboard
Numeric keypad, integrated with keyboard
Numeric keypad: ADM-3A video terminal (1976) with separate keypad
ADM-3A video terminal (1976) with separate keypad
Numeric keypad: Bluetooth numeric keypad, working also as calculator
Bluetooth numeric keypad, working also as calculator
Numeric keypad: A 104-key PC US English QWERTY keyboard layout with the numeric keypad at the far right
A 104-key PC US English QWERTY keyboard layout with the numeric keypad at the far right
Numeric keypad illustration

Worked examples

Example 1 — a first encounter with Numeric keypad

Start with the simplest possible case. Write down what Numeric keypad claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Numeric keypad before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Numeric keypad ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Numeric keypad

In research
Numeric keypad appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Numeric keypad in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Numeric keypad is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer keys, Japanese inventions, so understanding it makes those chapters shorter.
In everyday life
Look for Numeric keypad outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Numeric keypad in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Numeric keypad means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Numeric keypad out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Numeric keypad in simple terms?

A numeric keypad, number pad, numpad, or ten key, is the calculator-style group of ten numeric keys accompanied by other keys, usually on the far right side of computer keyboard. This grouping allows quick number entry with the right hand, without the need to use both hands on number row of main ke…

Why does Numeric keypad matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Numeric keypad?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Numeric keypad.

Tags

  • Computer keys
  • Japanese inventions

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