He calls the palm pilot 'hand pilot' and the calculator 'adding machine'. He does so to make fun of technology and to express his attitude towards technology (he does not think it is necessary).
In a store or online
99$ / 10$ rebate
She says her father has always said he wants her to excel in school / She will pay 10$ herself / She will clean up her room.
She will get an ice cream. Her mother promised her an icecream if the girl could talk her father into(=overhalen) buying a calculator that same day (and the girl talked her father into it).