£.s.d (Pounds stirling, shillings and pence) multiplication

[Brewins girl]

I've just looked at the responses to my original query (about £sd) and notice that I've had two people saying that 100 x £1.9s.10d is £149.3s.4d and two people saying it's £149.1s.4d. Now, what do I do with the two bob change if I go with the second of these? I've decided to write "nearly £150" and be done with it, but I thought people writing in this thread might be interested in seeing this collection of coins from the Festival of Britain in 1951. Unfortunately the 1d (one penny) coin is missing.

[groom]

It's £149. 3s 4d

£1 x 100 = £100
9s x 100 = 900s divided by 20 = £45
10d x 100 = 1000d divided by 240 = £4 with 40d left over
40d divided by 12 = 3s 4d

so £100 + £45 + £4 +3s + 4d = £149 3s 4d

[RJ_Paton]

It's £149. 3s 4d

£1 x 100 = £100
9s x 100 = 900s divided by 20 = £45
10d x 100 = 1000d divided by 240 = £4 with 40d left over
40d divided by 12 = 3s 4d

so £100 + £45 + £4 +3s + 4d = £149 3s 4d

The 1s and 4d comes from a simple error in mixing decimal and imperial

 1000d (100x10d) divided by 240 (pennies in a pound) does give an answer of 4.16 - the error comes in accepting the .16 to mean 16 pennies (or 1s and 4d) If you stick to plain old longdivision you have 1000 divided by 240 giving you £4 with 40d as a remainder - 40d as explained above  3s & 4d

[ThrelfallYorky]

- did someone need to spend a penny urgently?

[despair]

The reference to the "old groat"(fourpence) reminds me that at one time I think 4d was the cost of a phone call from a public phone box.If unconnected,you could "Press Button B" and get your four pence back.
On a more topical note 3d was the amount I remember that you got back when returning an empty bottle of Corona.
....and at one time(no,not in my lifetime)there were half and third farthings in circulation,originally intended for use in Ceylon and Malta respectively.

Regards
Roger