The research suggests firms are convinced that school standards are falling and that many think the Government should stop tinkering with exams.
The report from London University's Institute of Education and the Science, Technology and Mathematics Council warns that the country needs to upgrade learning to meet rising demand for mathematical skills.
Researchers spoke to 22 companies across the entire range of industries. All made extensive use of information technology. The ability to use spreadsheets and run a PC were increasingly important. Companies wanted employees to have a "feel" for numbers and percentages and be able to calculate and estimate.
Employers were bewildered by the range of maths qualifications, including GCSEs at different levels and vocational qualifications, and some were now using commercially produced tests instead. There was also a trend of qualification "inflation", as firms demanded A-levels or degrees.
The report, Mathematical Skills in the Workplace, coincides with a Government inquiry into the maths curriculum.
The challenge is to create courses that teach the basics and new skills for the workplace while also challenging mathematicians of the future. But one maths expert said the review brief was so wide that it was meaningless.
Half of teenagers fail to get a C or better in maths GCSE and the number applying to study a maths degree fell by more than 10 per cent last year.
Doug French, chair of the Maths Association secondary education committee, suggested problems with workers' IT skills should be dealt with by specific training, not in maths class. "A maths GCSE is an indication of general ability, not specific skills," he said.
Mathematical Skills in the Workplace by Celia Hoyles, Alison Wolf, Susan Molyneux-Hodgson and Phillip Kent is available at www.stmc.org.uk