Sum it - How to Play.

About Sum-It, from BoardGameGeek:

In the old days, Britain had a currency system of 12 pence to the shilling and 20 shillings to the pound. In 1971, Britain went metric and switched to 100 pence to the pound. This card game has a deck of cards in nominal amounts and Sum-It cards of the totals players must build to. When you reach your Sum-It, you call and show your cards. Get it wrong and deduct the penalty score, get it right and earn the points on the cards. The original edition is in l.s.d. and the later edition by Waddingtons is dated 1968, when the new coins were first issued, the game being styled as The Decimal Currency Game.