Author Topic: Arithmetic that makes you cringe  (Read 11171 times)

Re: Arithmetic that makes you cringe
« Reply #125 on: October 02, 2019, 01:41:43 pm »
No, you'd be putting 10 times too much on!

1ml = 10-6m3
1ha = 104m2
1ml/ha = 10-6/104m = 10-10m = 1 ångström

Mind you, my experience of applying agri-death is that it's nigh-impossible to spray anything like evenly.

Cudzoziemiec

  • Dormant but requires tea
Re: Arithmetic that makes you cringe
« Reply #126 on: October 02, 2019, 02:56:52 pm »
Financial analyst: What are the prospects for Product X?
Big boss: Product X sells £3.2 million, which is 8% of total sales. We have the capacity to increase that to 15%.
FA: Okay... my maths isn't that great.
BB: Alright, we can basically almost double it.
The unwilling rider and the one who leaves each control in turn without reluctance, with no desire to come back, obviously cannot be making the same journey, even though their brevets are identical.

T42

  • Tea tank
Re: Arithmetic that makes you cringe
« Reply #127 on: October 02, 2019, 03:26:26 pm »
Wikipedia tells me CGS = centimetre, gram, second and MKS = metre, kilogram, second. To my mind these are the same system, just at different scales. Isn't half the point of metric/SI that it's easy to relate between different scales because everything goes up and down in 10s, rather than an assortment of 12s, 16s, 20s and whatever in Imperial (and various other pre-metric systems)?

The danger with metric-based systems is losing track of the decimal point.  I did this during my A-level physics practical and the invigilator, who was wandering round making sure nobody was using a crafty AVOmeter, glanced at my pad and murmured "you might want to check that" as he passed my bench.
I've dusted all those old bottles and set them up straight.

fuaran

  • rothair gasta
Re: Arithmetic that makes you cringe
« Reply #128 on: October 02, 2019, 03:49:58 pm »
Financial analyst: What are the prospects for Product X?
Big boss: Product X sells £3.2 million, which is 8% of total sales. We have the capacity to increase that to 15%.
FA: Okay... my maths isn't that great.
BB: Alright, we can basically almost double it.
Depends on whether the total sales stay the same, or increase, or decrease...

Re: Arithmetic that makes you cringe
« Reply #129 on: October 02, 2019, 03:57:10 pm »
The danger with metric-based systems is losing track of the decimal point.  I did this during my A-level physics practical and the invigilator, who was wandering round making sure nobody was using a crafty AVOmeter, glanced at my pad and murmured "you might want to check that" as he passed my bench.
Indeed.  We (structural engineers) measure on site to mm, but work out loads in kN/m2 or kN/m.  Steel section serial sizes are related to the dimension in mm, but the tables of section properties quote Z in cm3 and I in cm4 (zenzizenzic centimetres, FYI).  Yield strengths of steels are quoted in MPa (N/mm2 or 103kN/m2).  Young's modulus is quoted in GPa (kN/mm2).

Cudzoziemiec

  • Dormant but requires tea
Re: Arithmetic that makes you cringe
« Reply #130 on: October 02, 2019, 04:20:59 pm »
Financial analyst: What are the prospects for Product X?
Big boss: Product X sells £3.2 million, which is 8% of total sales. We have the capacity to increase that to 15%.
FA: Okay... my maths isn't that great.
BB: Alright, we can basically almost double it.
Depends on whether the total sales stay the same, or increase, or decrease...
Not really. The question was about capacity not potential sales. The FA simply had to realize that 15 is approximately double 8.
The unwilling rider and the one who leaves each control in turn without reluctance, with no desire to come back, obviously cannot be making the same journey, even though their brevets are identical.