gistfile1.txt

$ cat numbers.yml
- hosts: localhost
  vars:
     i: "17"      # strings here like from register, etc.
     f: "92.87"
     s: "my name"
  tasks:
    - set_fact:
         numbers:
             my_i: "{{ i }}"
             my_f: "{{ f }}"
             my_s: "{{ s }}"

    - debug: var=numbers


$ ansible-playbook numbers.yml
TASK [debug] ************************************************************************
ok: [localhost] => {
    "numbers": {
        "my_f": "92.87",              <----- strings
        "my_i": "17",
        "my_s": "my name"
    }
}

$ ANSIBLE_JINJA2_NATIVE=True ansible-playbook numbers.yml
TASK [debug] ************************************************************************
ok: [localhost] => {
    "numbers": {
        "my_f": 92.87,              <----- NOT strings
        "my_i": 17,
        "my_s": "my name"
    }
}