This video tutorial on the Tech Math Channel introduces viewers to calculating percentages mentally. It begins with an explanation of what percentages are, breaking down the term into 'per' and 'cent', meaning out of 100. The tutorial then covers basic percentage calculations, such as finding 10%, 50%, and 5% of a number, and progresses to combining these to calculate percentages like 15% and 60%. Advanced calculations, such as determining 95% by subtracting 5% from 100%, are also demonstrated. The video concludes with practice problems to reinforce the concepts learned.

What is the main focus of the video?

• Learning to calculate percentages mentally

• Understanding complex algebra

• Learning geometry

• Solving calculus problems

What does 'percent' mean?

• Out of 100

• Out of 1000

• Out of 50

• Out of 10

How do you calculate 100% of a number?

• Add 10

• The number itself

• Divide by 2

• Multiply by 2

What is 50% of 80?

• 40

• 80

• 20

• 60

How do you find 10% of a number?

• Subtract 10

• Add 10

• Divide by 10

• Multiply by 10

What is 5% of 80?

• 8

• 16

• 40

• 4

How is 15% of a number calculated?

• 10% - 5%

• 5% + 5%

• 20% - 5%

• 10% + 5%

What is 60% of 42?

• 24.2

• 25.2

• 26.2

• 23.2

How do you calculate 95% of a number?

• Subtract 5% from 100%

• Multiply by 95

• Add 5% to 100%

• Divide by 95

What is 95% of 720?

• 690

• 700

• 710

• 684