Comparison to electronic digital calculators thumb|upright|December 1951 advertisement for the IBM 604 Electronic Calculating Punch explicitly comparing electronic computers to engineers calculating with slide rules Even during their heyday, slide rules never caught on with the general public.Stoll, Cliff. "When Slide Rules Ruled," Scientific American, May 2006, pp. 80–87. "The difficulty of learning to use slide rules discouraged their use among the hoi polloi. Yes, the occasional grocery store manager figured discounts on a slipstick, and this author once caught his high school English teacher calculating stats for trifecta horse-race winners on a slide rule during study hall. But slide rules never made it into daily life because you could not do simple addition and subtraction with them, not to mention the difficulty of keeping track of the decimal point. Slide rules remained tools for techies." Addition and subtraction are not well-supported operations on slide rules and doing a calculation on a slide rule tends to be slower than on a calculator.Watson, George H. "Problem-based learning and the three C's of technology," The Power of Problem-Based Learning, Barbara Duch, Susan Groh, Deborah Allen, eds., Stylus Publishing, LLC, 2001. "Numerical computations in freshman physics and chemistry were excruciating; however, this did not seem to be the case for those students fortunate enough to already own a calculator. I vividly recall that at the end of 1974, the students who were still using slide rules were given an additional 15 minutes on the final examination to compensate for the computational advantage afforded by the calculator, hardly adequate compensation in the opinions of the remaining slide rule practitioners." This led engineers to use mathematical equations that favored operations that were easy on a slide rule over more accurate but complex functions; these approximations could lead to inaccuracies and mistakes.Stoll, Cliff. "When Slide Rules Ruled," Scientific American, May 2006, pp. 80–87. "With computation moving literally at a hand's pace and the lack of precision a given, mathematicians worked to simplify complex problems. Because linear equations were friendlier to slide rules than more complex functions were, scientists struggled to linearize mathematical relations, often sweeping high-order or less significant terms under the computational carpet. So a car designer might calculate gas consumption by looking mainly at an engine's power, while ignoring how air friction varies with speed. Engineers developed shortcuts and rules of thumb. At their best, these measures led to time savings, insight and understanding. On the downside, these approximations could hide mistakes and lead to gross errors." On the other hand, the spatial, manual operation of slide rules cultivates in the user an intuition for numerical relationships and scale that people who have used only digital calculators often lack.Stoll, Cliff. "When Slide Rules Ruled", Scientific American, May 2006, pp. 80–87. "One effect was that users felt close to the numbers, aware of rounding-off errors and systematic inaccuracies, unlike users of today's computer-design programs. Chat with an engineer from the 1950s, and you will most likely hear a lament for the days when calculation went hand-in-hand with deeper comprehension. Instead of plugging numbers into a computer program, an engineer would understand the fine points of loads and stresses, voltages and currents, angles and distances. Numeric answers, crafted by hand, meant problem solving through knowledge and analysis rather than sheer number crunching." A slide rule will also display all the terms of a calculation along with the result, thus eliminating uncertainty about what calculation was actually performed. It has thus been compared with reverse Polish notation (RPN) implemented in electronic calculators.
comparison to electronic digital calculators thumb|upright|december 1951 advertisement for the ibm 604 electronic calculating punch explicitly comparing electronic computers to engineers calculating with slide rules even during their heyday slide rules never caught on with the general publicstoll cliff "when slide rules ruled" scientific american may 2006 pp 80–87 "the difficulty of learning to use slide rules discouraged their use among the hoi polloi yes the occasional grocery store manager figured discounts on a slipstick and this author once caught his high school english teacher calculating stats for trifecta horse-race winners on a slide rule during study hall but slide rules never made it into daily life because you could not do simple addition and subtraction with them not to mention the difficulty of keeping track of the decimal point slide rules remained tools for techies" addition and subtraction are not well-supported operations on slide rules and doing a calculation on a slide rule tends to be slower than on a calculatorwatson george h "problem-based learning and the three c's of technology" the power of problem-based learning barbara duch susan groh deborah allen eds stylus publishing llc 2001 "numerical computations in freshman physics and chemistry were excruciating; however this did not seem to be the case for those students fortunate enough to already own a calculator i vividly recall that at the end of 1974 the students who were still using slide rules were given an additional 15 minutes on the final examination to compensate for the computational advantage afforded by the calculator hardly adequate compensation in the opinions of the remaining slide rule practitioners" this led engineers to use mathematical equations that favored operations that were easy on a slide rule over more accurate but complex functions; these approximations could lead to inaccuracies and mistakesstoll cliff "when slide rules ruled" scientific american may 2006 pp 80–87 "with computation moving literally at a hand's pace and the lack of precision a given mathematicians worked to simplify complex problems because linear equations were friendlier to slide rules than more complex functions were scientists struggled to linearize mathematical relations often sweeping high-order or less significant terms under the computational carpet so a car designer might calculate gas consumption by looking mainly at an engine's power while ignoring how air friction varies with speed engineers developed shortcuts and rules of thumb at their best these measures led to time savings insight and understanding on the downside these approximations could hide mistakes and lead to gross errors" on the other hand the spatial manual operation of slide rules cultivates in the user an intuition for numerical relationships and scale that people who have used only digital calculators often lackstoll cliff "when slide rules ruled" scientific american may 2006 pp 80–87 "one effect was that users felt close to the numbers aware of rounding-off errors and systematic inaccuracies unlike users of today's computer-design programs chat with an engineer from the 1950s and you will most likely hear a lament for the days when calculation went hand-in-hand with deeper comprehension instead of plugging numbers into a computer program an engineer would understand the fine points of loads and stresses voltages and currents angles and distances numeric answers crafted by hand meant problem solving through knowledge and analysis rather than sheer number crunching" a slide rule will also display all the terms of a calculation along with the result thus eliminating uncertainty about what calculation was actually performed it has thus been compared with reverse polish notation (rpn) implemented in electronic calculators