In simple English… A number is divisible by 7 if the difference between 2 times the last digit and the remaining digits is divisible by 7.

Examples:

• Is 14 divisible by 7? 4*2=8. 8-1=7. Check.
• Is 28 divisible by 7? 8*2=16. 16-2=14. Check.
• Is 182 divisible by 7? 2*2=4. 18-4=14. Check.
• Is 1323 divisible by 7? 3*2=6. 132-6=126.
  • Is 126 divisible by 7? 6*2=12. 12-12=0. Check.

OP, if I have misunderstood your reasoning, please correct me.

Thanks, this is the answer I was looking for. I’m trying to save money because we don’t have a lot. My wife is on board with saving, but she hasn’t done the math to see where most of our money is going.

I might need to back off a bit. I like to save, but this might be a bit much.