How can I solve a rounding error using update_all in ruby on rails?

Assume there is a table named somethings with a column value of type float.

The schema is shown below.

# == Schema Information
#
# Table name: somethings
#
# id         :bigint   not null, primary key
# value      :float    not null
# created_at :datetime not null
# updated_at :datetime not null

Then, "update the value of all records in the somethings table to 0.4, then subtract 0.1".

The code is shown below.

Something.update_all("value = 0.4")
Something.update_all("value = value - 0.1")

After this operation, the value columns of the records in the somethings table are all 0.3000000000000000000000004, resulting in a rounding error.

I want to update without rounding errors, but how can I do it?

Note that I am aware that if I write the following without update_all, there will be no rounding error.

Something.update_all("value = 0.4")

Something.find_each do |s|
  s.update(value: (s.value.rationalize - 0.1.rationalize).to_f)
end

However, I would like to use update_all as much as possible for faster updates, as performance is severely degraded when the somethings table has a large number of records.