5 (five) is a number, numeral, and glyph. It is the natural number following 4 and preceding 6. The SI prefix for 10005 is peta (P), and for its reciprocal femto (f).

Five is the third prime number, after 2 and 3, and before 7. Because it can be written as 2^(2^1)+1, five is classified as a Fermat prime. 5 is the third Sophie Germain prime, the first safe prime, and the third Mersenne prime exponent. Five is the first Wilson prime and the third factorial prime, also an alternating factorial. It is an Eisenstein prime with no imaginary part and real part of the form 3n − 1. It is also the only number that is part of more than one pair of twin primes.

The number 5 is the 5th Fibonacci number, being 2 plus 3. 5 is also a Pell number and a Markov number, appearing in solutions to the Markov Diophantine equation: (1, 2, 5), (1, 5, 13), (2, 5, 29), (5, 13, 194), (5, 29, 433), ... (A030452 lists Markov numbers that appear in solutions where one of the other two terms is 5). Whereas 5 is unique in the Fibonacci sequence, in the Perrin sequence 5 is both the fifth and sixth Perrin numbers.

5 and 6 form a Ruth-Aaron pair under either definition. There are five solutions to Znám's problem of length 6. Five is the second Sierpinski number of the first kind, and can be written as S2=(2^2)+1 While polynomial equations of degree 4 and below can be solved with radicals, equations of degree 5 and higher cannot generally be so solved. This is the Abel-Ruffini theorem. This is related to the fact that the symmetric group Sn is a solvable group for n ≤ 4 and not solvable for n ≥ 5. While all graphs with 4 or fewer vertices are planar, there exists a graph with 5 vertices which is not planar: K5, the complete graph with 5 vertices. Five is also the number of Platonic solids. A polygon with five sides is a pentagon. Figurate numbers representing pentagons (including five) are called pentagonal numbers.

Five is also a square pyramidal number. Five is the only prime number to end in the digit 5, because all other numbers written with a 5 in the ones-place under the decimal system are multiples of five. As a consequence of this, 5 is in base 10 a 1-automorphic number. Vulgar fractions with 5 or 2 in the denominator do not yield infinite decimal expansions, as is the case with most primes, because they are prime factors of ten, the base. When written in the decimal system, all multiples of 5 will end in either 5 or 0. There are five Exceptional Lie groups. The number of terminal zeros in any number of numbers multiplied together will typically equal the number of 5's found in the prime factorization of the numbers. This means that multiplying the first 100 integers together will result in a number with 24 terminal zeros.

The Number 5 is:

* The number of oceans in the world.
* The five senses are sight, smell, hearing, touch and taste.
* The five basic tastes are sweet, salty, sour, bitter and umami.
* The number of the first books in the bible: Genesis (Bereisheet בראשית), Exodus (Shemot שמות), Leviticus (Vayikra ויקרא), Numbers (Bemidbar במדבר), and Deuteronomy (Devarim דברים)also known as the Pentateuch
* Most roses have five petals.
* Pentameter is verse with five repeating feet per line; iambic pentameter was the most popular form in Shakespeare.
* In the United States legal system, the Fifth Amendment to the United States Constitution can be referred to in court as "pleading the fifth", absolving the defendant from self-incrimination
* The note in the English monetary system that features Elizabeth Fry. (£5 Note)
* The smallest Euro banknote. It shows an antique bridge.
* The denomination of the U.S. dollar with Abraham Lincoln's portrait.
* The number of cents in a nickel.
* Kyle Busch's NASCAR Nextel Cup car number.
* The designation of an Interstate Highway that runs from San Diego, California to Blaine, Washington.
* The number of permanent members with veto power on the UN Security Council.
* The number necessary to make a majority decision in the U.S. Supreme Court.
* Five babies born at one time are quintuplets. The most famous set of quintuplets were the Dionne Quintuplets born in the 1930s.
* In Astrology, Leo is the 5th astrological sign of the Zodiac.
* Quintessence, meaning 'fifth element', refers to the elusive fifth element that completes the basic four elements (water, fire, air and earth). There is also a movie called The Fifth Element.
* The number of dots in a quincunx.
* The number of points in a pentagram.
* The Garden of Cyrus 1658 by Sir Thomas Browne is a Pythagorean Discourse based upon the number 5.
* The word "punch" comes from the Hindustani for five. Being true to the designation of punch, the drink Five Alive is named for its five ingredients.
* The holy number of Discordianism, as dictated by the Law of Fives.
* A popular Internet catch phrase commonly used on forums such as Something Awful. Posts are given a rating out of five. Posts which receive an average rating of five are referred to as 'top posts' or 'comedy gold'.
* There are 5 digits in a United States zip code
* An informal term for the British Security Service, MI5
* In tarot, card No. 5 is "the Hierophant".
* The typical number of members in a Super Sentai team.
* Human beings and other primates have five digits on each hand as well as five toes on each foot.
* The letter E is the fifth letter of the alphabet.
* May is the fifth month.
* The Blood street gang's number is 5

An internal business plan will often be developed in conjunction with a balanced scorecard or a list of critical success factors. This allows success of the plan to be measured using non-financial measures. Business plans that identify and target internal goals, but provide only general guidance on how they will be met are called strategic plans. Operational plans describe the goals of an internal organization, working group or department. Project plans, sometimes known as project frameworks, describe the goals of a particular project. They may also address the project's place within the organization's larger strategic goals.

Top 5 Tips for Effective Business Planning
1. Clearly define your business idea and be able to succinctly articulate it. Know your mission.
2. Examine your motives. Make sure that you have a passion for owning a business and for this particular business.
3. Be willing to commit to the hours, discipline, continuous learning and the frustrations of owning your own business.
4. Conduct a competitive analysis in your market, including products, prices, promotions, advertising, distribution, quality, service, and be aware of the outside influences that affect your business.
5. Seek help from other small businesses, vendors, professionals, government agencies, employees, trade associations and trade shows.

Top 5 Tips for Making the Most of Your Business Plan
1. Take the long view and do long-term planning. Map out where you want to be five years from now and how you plan to get there.
2. Write the plan yourself. You will learn more about your business by doing so.
3. Think of your plan as a living document. Review it regularly to make sure you are on track or to adjust it to market changes.
4. Share the plan with others who can help you get where you want to go—such as lenders, key employees and advisors.
5. Understand that you might pay a price in the short run to obtain long-term business growth and health.

Top 5 Tips on Building a Sound Business Plan
1. Write a business plan with a complete financial and marketing plan.
2. Your marketing strategy should be built around your strengths, your competitor's weaknesses and your customers' desires.
3. Test the reality of your business—know why it will work and how you will make it work. Think your business through step by step.
4. Allow at least two hours every week for thinking and planning. Do not allow anything to interfere with this time. You run the business. Don't let it run you.
5. Establish an annual operating plan. Review it and update it monthly with appropriate employees.