AmblesideOnline: British Money Circa 1900

1 penny = 1d
12 pennies = 1 shilling
240 pennies (20 shillings)  = 1£ ("pound sterling")

Using conversion rates for 1900:

1d (1 denarius, or 1 pence/penny) = 2 1/4 US cents  ($0.54 by today's inflation rates for Dec 2006)
1s (1 shilling) = 27 US cents ($6.48 by today's inflation rates)
1£ (1 pound) = $5.40 US dollars ($129.65 by today's inflation rates)

Pound (signified by the lira sign: £) is sometimes abbreviated "lb" because it comes from the word "librae."
"The pound sign derives from the black-letter "L", from the abbreviation LSD -- librae, solidi, denarii -- used for the pounds, shillings and pence of the original duodecimal currency system. Libra was the basic Roman unit of weight, which in turn derived from the Latin word for scales or balance." (from Wikipedia)

1d would have been about 2 1/4 cents, equivalent to 54 cents today.
2d would have been about 4 1/2 cents, equivalent to $1.08 today.
3d would have been almost 7 cents, equivalent to $1.62 today.
4d would have been 9 cents, equivalent to $2.16 today.
5d would have been about 11 cents, equivalent to $2.70 today.
6d would have been about 13 1/2 cents, equivalent to $3.00 today.
7d would have been almost 16 cents, equivalent to $3.78 today.
8d would have been 18 cents, equivalent to $4.32 today.
9d would have been about 20 cents, equivalent to $4.86 today.
10d would have been 22 1/2 cents, equivalent to $5.40 today.
11d would have been almost 25 cents, equivalent to $5.94 today.
12d would have been 27 cents, equivalent to $6.48 today.

1s would have been 27 cents, equivalent to $6.48 today.
2s would have been 54 cents, equivalent to $12.96 today.
3s would have been 81 cents, equivalent to $19.44 today.
4s would have been 1.08 cents, equivalent to $25.92 today.
5s would have been 1.35 cents, equivalent to $32.40 today.
6s would have been 1.62 cents, equivalent to $38.88 today.
7s would have been 1.89 cents, equivalent to $45.36 today.
8s would have been 2.16 cents, equivalent to $51.84 today.
9s would have been 2.43 cents, equivalent to $58.32 today.
10s would have been 2.70 cents, equivalent to $64.80 today.
11s would have been 2.97 cents, equivalent to $71.28 today.
12s would have been 3.24 cents, equivalent to $77.76 today.
13s would have been 3.51 cents, equivalent to $84.24 today.
14s would have been 3.78 cents, equivalent to $90.72 today.
15s would have been 4.05 cents, equivalent to $97.20 today.
16s would have been 4.32 cents, equivalent to $103.68 today.
17s would have been 4.59 cents, equivalent to $110.16 today.
18s would have been 4.86 cents, equivalent to $116.64 today.
19s would have been 5.13 cents, equivalent to $123.12 today.
20s would have been 5.40 cents, equivalent to $129.60 today.

Fractionated prices are read as shilling/pence:
2/6 = 2 shillings sixpence or about 68 US cents, equivalent to $15.96 today.
2/8 = 2 shillings eightpence or about
5/- = 5 shillings (no pence) or about $1.35 in the US in 1900, which would be equivalent to $32.40 today.
6/6 = 6 shillings sixpence or $1.75 in the US in 1900, equivalent to $41.88 today.