Why your till should count in pennies, never pounds
Store £4.50 as a decimal and sooner or later a rounding error turns a five-kitchen split into a total that is a penny out. Every figure here is whole pennies until the instant it is shown. That is not fussiness — it is how the split adds up.
Computers are bad at decimals. Not a little bad — 0.1 plus 0.2 does not equal 0.3 in most programming languages, it equals 0.30000000000000004. On a single receipt that never shows. Across a busy day of splitting one payment between five kitchens, a tip, and a hall fee, it shows up as a total that is a penny out and a report nobody can reconcile.
Whole numbers all the way through
So nothing in this system stores money as pounds-and-pence decimals. A price is held as a whole number of pennies — 450, not 4.50 — from the moment it is entered to the moment it is displayed, and only then turned back into "£4.50" for a human to read. Every sum, every split, every fee is integer arithmetic, which computers do exactly.
Where it earns its keep
The place this matters most is the one thing a food hall does that a single shop never has to: divide one guest payment across several traders. A tip spread over five kitchens, a delivery charge apportioned, a promotion discounted — each is whole pennies shared by one routine that guarantees the parts add back to the whole, with no stray penny invented or lost. Menu prices, for the record, are held inclusive of VAT, because that is the number on the shelf edge.
You will never see any of this, and that is the point. Money that is counted in whole units is money that reconciles — and a settlement a kitchen can check by hand is a settlement it does not dispute.