Determining if a number is divisible by 7 can be done using a simple method. Here’s a step-by-step guide:
- Take the number: Start with the number you want to check for divisibility by 7. For example, let’s say the number is 203.
- Double the last digit: Take the last digit of the number (in this case, 3) and double it. So, 3 x 2 = 6.
- Subtract from the rest: Now, subtract this doubled value from the rest of the number after removing the last digit. The rest of the number is 20, so you perform the calculation 20 – 6 = 14.
- Check the result: Now, check if the result (14) is divisible by 7. Since 14 ÷ 7 = 2, which is a whole number, we can conclude that 203 is divisible by 7.
- Repeat if necessary: If the result was not easily recognizable as divisible by 7, you could repeat this process on the new number until you reach a conclusion.
This method is effective for any whole number, and can even be used on negative numbers. It’s a practical trick that helps simplify the process of finding out if a number is divisible by 7!