Divisibility by 7 Techniques

The video tutorial explains a technique to determine if a number is divisible by 7. The method involves taking the last digit of the number, multiplying it by two, and subtracting this from the remaining digits. If the result is divisible by 7, then the entire number is divisible by 7. The video provides an example with the number 525 and verifies the result by showing that 75 multiplied by 7 equals 525. It also addresses what to do if one is unsure about the divisibility of the resulting number, suggesting repeating the process.

What is the first step in determining if a number is divisible by 7 using the technique described?

• Subtract the last digit from the remaining digits

• Divide the number by 7

• Multiply the last digit by two

• Add the last digit to the remaining digits

After multiplying the last digit by two, what should you do next according to the technique?

• Divide the result by 7

• Subtract the result from the remaining digits

• Add the result to the remaining digits

• Multiply the result by 7

In the example provided, which number is used to demonstrate the divisibility by 7?

• 35

• 56

• 42

• 49

What should you do if you are unsure whether the resulting number is divisible by 7?

• Repeat the process with the new number

• Add 7 to the number

• Multiply the number by 7

• Subtract 7 from the number

What is the result of multiplying 75 by 7, as mentioned in the video?

• 525

• 515

• 535

• 500