It happened to Gary H. Arlen of Bethesda as it has happened to so many of us. He was unpacking some glassware that had been stored away for a long time and began reading the newspaper that had been used as packing. His eye happened to fall upon the prices in a Peoples Drug Stores ad.

Kleenex was 2 for 57 - and these were boxes of 280, not 200. Twenty Hershey bars were 56 cents. Bottles of Bayer Aspirin, each containing 100 tablets, were 2 for $1.07. Two 28 ounce bottles of Top Job could be had for 69 cents. Budweiser was 18 cents a can. For 98 cents, you could get 140 Band-Aids. A half-gallon of mouthwash - that's what I said, a half-gallon - was 67 cents. Ice cream? Five pints for $1.

No, gary's newspaper wasn't dated 1897. It was dated April 2, 1970.

I could quote you statistics on how much the average family's income has increased since 1970, and how much the average hourly wage has increased since then, but neither of these figures would mean much to any particular individual. If you'd like to know whether your own income has been keeping pace with inflation, there's a simple way to find out.

Figure the percentages of the various price increases, then find an average for them. Once that's done, dig out your income tax records, refresh your memory on how much you made in 1970, and figure the percentage of increase you have schieved since then.

Compare the percentage of average price increase to the percentage of income increase. If they match, you're standing still. If your pay has gone up less than prices have, don't cry on my shoulder; tell your boss. If your pay has gone up more than prices, congratulations. I'll bet there aren't many openings where you work.

My recollection is that percentages are figured thus: Subtract the old price (or wage) from the new. Divide the old into the difference between old and new. Multiply the quotient by 100 (move the decimal point two places to the right) and you have percentage of increase.

Example: The old price was 59 cents. The new price is 98 cents. The difference is 39 cents.

Divide 59 into 39. Multiply by 100. The percentage of increase is 66.

The big question is how much wages have risen since 1970. Yours may have increased more than you realize.

But the dollars you worked so hard to save in 1970 now buy fewer Hershey bars, fewer cans of beer, less mouthwash and - alas! - less aspirin.

Apparently there are only two ways to beat inflation: Spend every cent you take in as fast as possible to avoid accumulating savings. Or die early.