Want to save money on groceries?

Bring a calculator along with your shopping list - and don't forget your reading glasses, to get a good look at the small print on labels.

That's among the first lessons taught to the low-income adult participants in ShoppingMatters.org, a free, guided grocery-store tour developed by the nonprofit organization Share Our Strength. The tour focuses on finding the best nutrition at the best price.

Calculators are so important that Shopping Matters trainers make sure each participant gets one to keep.

"Sometimes unit pricing is tricky, because they'll have a number for the cost per ounce for one brand, and the cost per pound for the same thing in a smaller or larger size," explained Christina Miller, a registered dietitian with Shopping Matters.

At the King Soopers near West 58th Avenue and Ralston Road in Arvada recently Miller pointed to a display featuring cans of Kuner's beans. Was the 30-ounce can cheaper than the 14-ounce can? The unit price for the larger can was listed in ounces, the unit price for the small can in pounds.

After Miller did a little tapping on her calculator, the price worked out to 6 cents an ounce for the smaller can, and 4.87 cents per ounce for the larger can.

"But then you need to ask whether you'll use all 30 ounces in your meal, or if you'll eat the rest later, because it's not cheaper if you end up throwing away some of the food," she said, "In that case, buy the smaller can."

That pragmatic thinking characterizes the decisions taught in Shopping Matters. The program's first rule:

Shop only after you've eaten. A hungry shopper, Miller says, is too susceptible to impulse purchases.

The second rule: Always shop with a list and know the ingredients in your pantry.

If that's hard to envision, think about grocery shopping in terms of Shopping Matters' "\$10 Challenge":

Can you find one whole-grain product, one dairy product, one fruit, one vegetable and one lean-protein source to create a main meal for \$10 or less?

Succeeding at the \$10 Challenge means studying nutrition content (fiber, sodium, trans fats, protein), putting that calculator to work and reading the ingredient listing.

"There's so much labeling on a package that it can be deceiving," said Reneé Petrillo, another dietitian and Shopping Matters facilitator, before heading toward a display of store-brand breads. In addition to the white sandwich bread, there was brown bread labeled "wheat," suggesting it was whole-wheat bread. But on closer inspection, "whole wheat flour" wasn't even listed in the ingredients. Sometimes manufacturers use molasses to color the bread, Miller said.

"That's why it's important to read ingre-dients," Petrillo said. "Make sure the first ingredient is whole wheat. And then look at the nutrition facts. The whole-wheat bread has 2 grams of fiber in one slice. The wheat bread has 1 gram of fiber in two slices. Which bread will keep you full longer?"

Answer: The whole-wheat bread. It costs 70 cents more, but Petrillo considers that money both well-spent and cost-effective, since it would take twice as much of the cheaper bread to sate an appetite.

In the produce department, Miller and Petrillo nudge Shopping Matters participants toward buying whole fruits, instead of the packaged, diced or sliced versions.

One pound of strawberries was \$2.50, stems intact. One pound of prepared fruit - strawberries minus their green stems - cost \$5.49 per pound.

"Sometimes it can be cost-effective to buy the packaged food, if you know you'll only eat a few slices vs. wasting the rest of the melon," Miller observed.

The \$10 Challenge
The concept: Buy one item from each of five food groups - whole grain, dairy, lean protein, fruit, vegetable - that can be incorporated into a nutritious meal for \$10 or less. Also, use items available in your pantry.
Natural Grocers by Vitamin Cottage
Three bananas: 62 cents
Two garnet yams (\$1.89 lb.): \$1.68
16-oz. package Nine Grain Cereal: \$1
6-oz. lemon-flavored yogurt: \$1.25
One dozen large white eggs: \$2.25

The meal:
Using olive oil, chicken broth, chickpeas, garlic and onions from the pantry, make a pilaf from the cereal. Cut the yams into slices and bake until caramelized at 400 degrees. For a dessert that combines protein and a sweet, use flour and butter from the pantry to make crepes from half of the dozen eggs. Fill them with cream cheese and sliced bananas and top it with yogurt.
Total amount of the \$10 used: \$6.80
Safeway
Smart Balance peanut butter: \$3.34
One carrot: 34 cents
6-ounce nonfat vanilla yogurt: \$1.50
Package of whole-wheat pasta: \$1.25
10-ounce package strawberries: \$3.00

The meal:
Using peanut butter, plus soy sauce, sesame paste, rice vinegar and other spices from the pantry, make Szechuan sauce to coat the cooked and cooled pasta for cold noodles with sesame sauce. Shred carrot and mix into the pasta. Slice strawberries, and mix with vanilla yogurt. (Note: Both the peanut butter and the pasta were found in a discount bin at the back of the store.)

Total amount of the \$10 used: \$9.42