Divisibility Rules and Subtraction

The video tutorial from Mumu Math and Science explains how to determine if a number is divisible by seven using a specific technique. The method involves taking the last digit of the number, multiplying it by two, and subtracting it from the remaining number. If the result is zero or seven, the original number is divisible by seven. The video provides three examples to illustrate this technique: 252, 882, and 910. Each example is broken down step-by-step to demonstrate the process. The video concludes with a motivational message about kindness.

What is the first step in determining if a number is divisible by seven?

• Add the last digit to the rest of the number

• Multiply the last digit by two

• Subtract the last digit from the rest of the number

• Divide the number by seven

In the example with 252, what is the result after subtracting the doubled last digit from the rest of the number?

• 4

• 21

• 25

• 36

How many times does 7 go into 252?

• 35

• 36

• 37

• 38

What is the result after the first subtraction in the example with 882?

• 88

• 82

• 84

• 80

What is the final result after repeating the process with 882?

• 0

• 14

• 21

• 7

In the example with 910, what is the result after subtracting the doubled last digit from the rest of the number?

• 9

• 7

• 0

• 91

What is the final result after applying the divisibility rule to 910?

• 21

• 7

• 0

• 14