For many engineers, the number 145 is a good number. Most non-engineers (NE’s) may think this is because 145 is a low estimate of the engineer’s IQ – all right, maybe not MOST, but there are surely one or two gullible NE’s.

145 could represent the number of people the engineer found out was going to be at his upcoming presentation, causing him to throw up in anticipation.

145 may represent the number of times the single engineer practiced the “speech” to ask out a girl, until he realized that there was no way he would get through it without writing it down.

145 might represent the number of times the engineer with kids has told them “No” to the frivolous request of wanting to buy a new car, or even a new used one. The ’97 minivan is running great.

But 145 actually is – and here is the exciting part so please stand near my NE friend Tom when he reads this in case he faints – a good estimate for the density of concrete. 145 pounds per cubic foot is what concrete typically is in terms of (English system) density. Sure, if it is reinforced or made denser with additives, it may get up to or over 150 pcf. There are ways to bring it down below 140 pcf. But 145 is a good, sound number to use in any calculation.

In case any of you NE’s out there are on a game show and they show you a cube of concrete one foot in dimension on each side, you will now know the answer of how much it weighs, so that you can move on to the next round. You’re welcome.