Work out percentage discounts instantly! | Summary and Q&A

TL;DR

Learn how to quickly and easily calculate percentages mentally for discounts and sales, using simple tricks and concepts.

Key Insights

• 💦 Taking off a percentage is equivalent to working with a percentage of the original number.
• ❓ Quickly calculating percentages like 10%, 50%, 10%, and 5% can simplify mental calculations.
• 🦻 Understanding the concept of percentages and fractions can aid in mentally calculating discounts and sales.
• 🍳 The trick is to break down percentages into simpler components and add them together.
• 🐎 Practice and familiarity with these mental calculation techniques will improve speed and accuracy.
• 💦 Mental calculations work best for simpler percentages like 10%, 25%, 30%, and 50%.
• 😄 As numbers become more complex, it may be helpful to round or approximate to ease mental calculations.

Transcript

good welcome to the tech math Channel what we're going to be having a look at in this video is we're going to be looking about how to mentally take off a percentage and the reason for this is because quite often you go into a shop and they'll or a store and they'll have something like uh you know 25% off this amount or 20% from this amount or 50% o... Read More

Questions & Answers

Q: How can I mentally calculate percentages for discounts and sales?

To mentally calculate percentages, remember that taking off a percentage is the same as working with a percentage of the original number. Use tricks like quickly calculating 10%, 50%, 10%, and 5% to simplify the calculations.

Q: What is the trick to quickly calculating percentages like 10%, 50%, 10%, and 5%?

The trick is to remember that 100% is the whole number, 50% is half of 100%, 10% is 1/10 of 100%, and 5% is 1/10 of 50%. For example, for a number like $20, 10% is $2, 50% is $10, and 5% is $1.

Q: How do I calculate a discount of 20% off a number like $20 mentally?

To mentally calculate a 20% discount, remember that taking off 20% is the same as working with 80% of the number. For $20, 80% is equivalent to $16.

Q: How do I calculate a discount of 30% off a number like $40 mentally?

To mentally calculate a 30% discount, remember that taking off 30% is the same as working with 70% of the number. For $40, 70% is equivalent to $28.

Summary & Key Takeaways

• This video teaches viewers how to mentally calculate percentages for discounts and sales.

• The key concept is understanding that taking off a percentage is the same as working with a percentage of the original number.

• The video introduces the trick of quickly calculating percentages like 10%, 50%, 10%, and 5% to simplify the calculations.