There's a "new math" of home owning and selling that's rapidly changing the way real estate is priced in transactions across the country.

But unlike the new math that perplexed an entire generation of parents and kids, real estate's version is relatively easy to comprehend, with the help of standard financial tables, and highly practical.

It often saves buyers and sellers hard cash. It makes sales go through for hard-pressed brokers and builders. And very possibly, it will be an integral part of the way local property tax assessors set the market value of your home in the near future.

So if you're considering plunging into the real estate market anytime soon--as seller, purchaser or both--you ought to become conversant with the principles of the new math. Here's a quick overview to give you a head start:

First of all, shed your ingrained notions about "price." In the new math of real estate, price is merely part of an equation, not an end in itself. The house you own or want to buy, in other words, has at least several fair-market prices, and perhaps dozens of them.

Price, in the cold, hard light of 1982, is governed entirely by the terms of the financing you attach to the property. The new math helps you set that price.

It stands to reason, for example, that a house with assumable, single-digit FHA or VA financing is going to command a higher price than an identical property next door with no financing attached.

The house with an antique FHA loan and a big seller take-back of a second mortgage will command a premium price, say $100,000. The neighbor's house that can only be financed with a new 17 percent adjustable-rate loan from a bank may go for as little as $87,000. That is the rock-bottom or "cash" value of the house in today's market.

The value of the financing of the first house, in short, was worth $13,000, expressed in the price.

But what if the same house were owned free and clear, and the seller could afford to provide a large first mortgage or deed of trust? Put yourself in the position of the owner. You offer a buyer a $75,000 loan, and you want at least a 12 percent return on your deferred money. Let's say also that the buyer can't afford to pay more than $630 a month--which is $140 less than you need as the seller. (The monthly principal and interest on a standard $75,000 mortgage at 12 percent is $770.)

What"price" should the house now carry in order to make the deal go through? How do you adjust the key elements in the transaction to satisfy both your needs and those of the buyer?

The answer comes form Les Glickman, vice president of St. Louis' Ira E. Berry real estate firm, and one of the nation's leading exponents of the new math.

Glickman uses a handy paperback book filled with financial tables to figure that a payment of $630 per month on a $75,000 loan translates out to an effective interest rate of 9 1/2 percent. All the buyer can actually afford on a monthly basis, in other words, is a 9 1/2 percent loan.

You, the lender--who absolutely insist on a minimum 12 percent return--can now tinker with your price and loan terms, and still come out whole. Using Glickman's new math tables, you come up with the following:

Add about $7,000 to the selling price of the house, making it $107,000. Offer the buyer a $75,000 first mortgage or deed of trust, a 9 1/2 percent interest rate, and a five-year term. Payments are set as if the loan were a standard 30-year note, but the entire debt comes due in five years.

The $7,000 higher price and shorter-term financing, according to Glickman's computations, will compensate you fully for the cut-rate 9 1/2 percent loan versus the 12 percent you wanted. Meanwhile the monthly payments of $630 will enable your would-be purchaser to buy at his current income.

At the end of the five-year term, of course, the purchaser will have to refinance. But that's nothing unusual. Balloon terms of three to five years have been a fact of life for virtually anyone purchasing real estate at below-market prices for the past 18 months. There's no sign that's going to change, either.

The essential point about the new math is this: Houses can sell, no matter what the market conditions, if buyers and sellers understand the "cash value" equivalents of different forms of financing. Selling price--which used to be synonymous with "value"--isn't synonymous anymore. It's often not even close.

"You can only look at price in the context of the financing terms and rates," counsels Glickman, a frequent lecturer on the subject. "There is no single 'price' per se. Every house has a bunch of them."

Multiple-listing services and property-tax assessments that simply present "prices"--without providing the financial terms in detail--are relics of an earlier era, in Glickman's view. "Until they crank financing into the equation," he says, "you don't know your true value in 1982."

The "new math" book Glickman uses is called "Financial Loan Terms" (Computofacts, 209 Sheppard Ave. East, Willowdale, Ontario, Canada M2NSW2, $9.00 postpaid).