The Dell venue was supplied with Windows 7 which I updated to 10. For the first 3 months it did pop up the numeral pad. Then it suddenly stopped. I've just tried it without the keyboad and mouse and...

Windows 10 on dell venue tablet with bluetooth keyboard and usb mouse.
On start up sign in to MS account by pin rather than password selected.
When click on pin, a numeral pad used to pop up and...