How to find remainder of a division in Ruby?

I'm trying to get the remainder of a division using Ruby.

Let's say we're trying to divide 208 by 11.

The final should be "18 with a remainder of 10"...what I ultimately need is that 10.

Here's what I've got so far, but it chokes in this use case (saying the remainder is 0).

division = 208.to_f / 11
rounded = (division*10).ceil/10.0
remainder = rounded.round(1).to_s.last.to_i

The modulo operator:

> 208 % 11
=> 10

If you need just the integer portion, use integers with the / operator, or the Numeric#div method:

quotient = 208 / 11
#=> 18

quotient = 208.0.div 11
#=> 18

If you need just the remainder, use the % operator or the Numeric#modulo method:

modulus = 208 % 11
#=> 10

modulus = 208.0.modulo 11
#=> 10.0

If you need both, use the Numeric#divmod method. This even works if either the receiver or argument is a float:

quotient, modulus = 208.divmod(11)
#=> [18, 10]

208.0.divmod(11)
#=> [18, 10.0]

208.divmod(11.0)
#=> [18, 10.0]

Also of interest is the Numeric#remainder method. The differences between all of these can be seen in the documentation for divmod.

please use Numeric#remainder because mod is not remainder

Modulo:

5.modulo(3)
#=> 2
5.modulo(-3)
#=> -1

Remainder:

5.remainder(3)
#=> 2
5.remainder(-3)
#=> 2

here is the link discussing the problem https://rob.conery.io/2018/08/21/mod-and-remainder-are-not-the-same/