Work out percentage discounts instantly!

TL;DR

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

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

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.

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.