Break a number into prime factors
Write 84 as a product of primes: 2 × 2 × 3 × 7.
Prime factorization breaks a number into primes that multiply to give it. Divide by the smallest prime that fits, again and again, until you reach 1.
Classic CAS
Start on the main screen: Press home to open the Home menu (Calculator, Graphs, Settings, and more). Choose Calculator, or press esc to go back to the calculation page.
Press menu, then 2 for Number and 3 for factor(. Type 84 and press enter.
menu2384enter
You should seefactor(84 2^2·3·7
The answer 2^2·3·7 means 2² × 3 × 7.
Classic Graphing 84 · Dividing by hand
Start on the main screen: Press 2nd then mode (QUIT) to get back to the home screen. Pressing clear on a menu also backs out of it.
Start with 84 and press enter. It is even, so divide by 2 and press enter. The answer is 42.
84enter÷2enter42 is still even. Divide by 2 again to get 21.
÷2enter21 is not even but divides by 3. The result, 7, is prime. So 84 = 2 × 2 × 3 × 7.
÷3enter
You should seeAns/2 Ans/3 7
Tips
- Test primes in order: 2, 3, 5, 7, 11. You only need to try primes up to the square root of the number.