An electronics company wanted to develop a new product for the British market. They had a ________ interesting idea for a calculator with big keys, so that older people could use it easily. They did some market research and found that people would buy it if it was _________ quality. Respondents also mentioned that they wouldn't want anything too _______ or complicated to use. It also had to be _________ and not need new batteries regularly. 'It would be very __________ when shopping, one lady remarked. A few months after sales had started, they carried out further research, and found that the new solar-powered calculator was very _________ with younger people too, as they thought the bright colours and big keys were very _________ . Feedback has been _________ positive: older people find it _______ , while teenagers think it's __________ for money at only £10.