Tommy Steele in "Half a Two and A Half New Pence"
When I was about nine I went to buy an Airfix model. However, models were 2/3 then; I thought I had a half a crown (2/6) but I only had a florin (2/-). That's OK, said the owner, you can give me the thruppence (3d) next time you come in. Then my family went abroad for 10 months. When I came back to Blighty I went to the model shop and gave the man his thruppence. He'd forgotten about it all by then, but recognising an attempt at honesty rewarded me with a couple of tubes of modelling glue worth a tanner (6d).
Let's see, in modern parlance: I went to buy a 11 and 1/4p model, but I only had 10p when I thought I had 12 and 1/2p. That's OK, bring me the extra 1 and 1/4p next time....etc etc.
No, tell it to the kids today and they won't believe you. No-one hands two tubes of glue to a nine-year-old these days.