The U.S. government is providing the adage: pennywise, pound-foolish. It's thinking about abolishing the one-cent coin, to save the Treasury the cost of making it - but at enormous potential cost to the rest of us.

The Treasury's case in this: Demand for pennies is growing rapidly. Unless something is done, a new mint will have to be built in Denver at a cost of $65 million. If pennies were abolished - replaced, perhaps, by two-cents - we not only would save the cost of the new mint but also millions of dollars in metals, personnel, shipping and storage.

But what happens to consumer prices if pennies are eliminated? It may be true that nothing costs a penny anymore, but this had no bearing on the importance of pennies in commerce.

Millions of items carry price tags that end in one, three, five, seven or nine cents. If only two-cent pieces existed, the majority of those prices probable would be increased a penny.

It's possible half the prices might be rounded down a penny, so as to give the merchants the same profit margin they had before the change in coinage. But the temptation to "round up" by just a silly penny probable would be irresistible.

Anti-penny people argue that prices may not change, in fact. For example grocery stores might continue to use odd prices, then add a penny to the final bill if the total didn't come to an even number.But it seems more likely that all items soon would carry price tags ending in two, four, six or eight cents.

If every man, woman and child in the United States paid only 10 cents more a week because of prices being rounded up a penny, the annual cost would come to $1.1 billion - enough to build 17 Denver mints.

Other coins have been abolished successfully. Half-cent, two-cent and three-cent coins were struck at various times in the 19th Century. But when they were abandoned, they already had fallen into disuse.

The penny, by contrast, is American's most popular coin. Millions of people save pennies in piggybanks, glass jars, and coin collections. All told, some 31 per cent of the coins minted have been taken out of circulation by savers. Another 10 per cent are lost or abandoned. But the remainder continue to circulate.

Some 11 billion pennies were minted last year. At present rates of demand, 12 to 15 billion will be needed by 1980, and 25 billion by 1990. The vast majority of all the coins in circulation are pennies.

Abolishing pennies isn't the only way out of the Treasury's cost dilema . The government could switch to aluminum cents, because more of them can be made on the same equipment. The last time this idea came up, it was defeated roundly by lobbyists for the vending machine industry. But their claim to consideration surely should take second place to that of consumers at large.

Another course is to mint some two-cent coins with pennies, and make proportionately fewer pennies. Then, no price changes would be needed.