A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

How can you quickly calculate 20 percent of any bill amount?

  • This Question is Open
  1. Hero
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Suppose you have $25. Move the decimal one place to the left to get 10%. Now you have $2.50 Multiply that by 2 to get 20%. Now you have $5

  2. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    divide by 5 (I suppose).

  3. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    either way... would have been better using an american computer and keyboard tho. bye:)

  4. terenzreignz
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Will it be easier to do Hero's method in reverse? ie Double it first and then move the dot?

  5. Hero
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    If you want to find 30% of $25, again move the decimal one to the left: $2.50. Then multiply by 3 to get $7.50

  6. Hero
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The point is, it is possible to do this in your head without a calc.

  7. Hero
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Finding percentages of numbers can be a "mental math" activity.

  8. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.