Helping Your Child Learn Mathematics - Activities: Mathematics at the Grocery Store

One Potato, Two Potatoes 
Preschool

		Use advertising flyers or newspaper advertisements to help your child identify, classify and count items. Ask, for example, "How many cans of soup are there?" "What vegetables do you see?" and so forth.

Making a grocery shopping list can be both enjoyable and an opportunity to reinforce young children's number sense.

What You Need

• List of grocery items
• Color pictures of grocery items cut from magazines, catalogs or advertising flyers (for example, choose pictures of different kinds of vegetables, fruit, containers of milk or juice, cans of soup, boxes of cereal and crackers, loaves of bread)
• Index cards (or similar-sized cards cut from heavy paper)
• Glue stick
• Small box (large enough to hold the cards)

What to Do

• Put together the set of food pictures and help your child paste each picture onto a card. Then have your child sit with you as you make up a grocery shopping list. Read the list aloud to her, item by item, saying, for example, "We need to buy milk. Find the picture of the milk." When the child finds the picture, have her put it in the box. Continue through the list, asking her to find pictures of such things as apples, potatoes, bread, soup and juice.

• When you've finished, ask your child to tell you how many things you need to buy, then help her to count the pictures in the box.

• Ask your child to put all the pictures of vegetables in one group, then all the pictures of fruit in another group. (You might continue with items that are in cans, items that are in boxes and so on.)

• Point to one group of pictures, such as the fruit. Help her to count the number of pictures in that group. Have her do the same for other groups.

Ready, Set, Shop!
Kindergarten-Grade 1

		Using the advertised prices in a newspaper or flyer to estimate the cost of items on a shopping list can help children sharpen their mental math and estimation abilities.

Grocery shopping offers opportunities to let children apply a range of mathematics skills, including data collection and estimation.

What You Need

• Pencil and paper
• Calculator

What to Do

• To help your child learn about collecting data, involve him in making a shopping list for a special occasion, such as his birthday party. As you discuss what you need to buy, write out a list of grocery items. Then review the list with your child and tell him to make a check mark next to each item that you name. If you need more than one of an item, such as cartons of ice cream, tell him how many checks to make beside that item. Review the list with him and have him tell you what items-and how many of each—that you need to buy.

• Ask your child to choose something that he wants for dinner—a cake, a salad, tacos. Have him check to see what ingredients you already have, then ask him to help you make a shopping list. At the grocery store, let him find each item on the list. Help him to compare prices for different brands of the same items (such as boxes of cake mix) to see which items are the best buys.

• Ask your child questions such as, "Which is cheaper, this package of two tomatoes for $1.50 or three of these tomatoes at 60 cents each?" Have him estimate, then check his answer with a calculator.

Get into Shapes
Kindergarten-Grade 1

		Before shopping trips, review different shapes with children by pointing them out in items around the house. Encourage them to use the correct name for each shape: square, rectangle, triangle, circle, cube, cylinder and so forth.

Being able to recognize how different shapes are used in common settings helps children to understand geometric principles-such as shape and quantity-and the relationships among them.

What to Do

• At the store, ask your child questions to focus her attention on the shapes that you see. Ask her to find, for example, items that have circles or triangles on them or boxes that are in the form of a cube or a rectangular solid.

• As you shop, point out shapes of products—rolls of paper towels, unusually shaped bottles, cookie boxes shaped like houses. Talk with your child about the shapes. Ask her why she thinks products, such as paper towels and packages of napkins, come in different shapes. Have her notice which shapes stack easily. Try to find a stack of products that looks like a pyramid.

Ask your child for reasons the shapes of products and packages are important to store owners. (Some shapes stack more easily than others and can save space.)

Clip and Save
Grades 1-2

		Help children feel that they're a part of family budgeting by encouraging them to look in newspapers and flyers for coupons for items that the family uses. Have them look for coupons for items that they want to buy with allowance or birthday money.

Coupons can be used to help children learn the value of money as well as to let them show off their addition and subtraction skills.

What You Need

• Pennies, nickels, dimes, quarters
• Grocery store coupons
• Pencil and paper

What to Do

• Show your child a grocery store coupon for a product that he likes to eat and have him count out coins to show how much money the coupon saves on the product. For example, if the coupon is for 30 cents off a jar of peanut butter, give your child nickels and dimes and tell him to count out three dimes or six nickels. Give your child all the coins and challenge him to figure out how many different coin combinations he can make to total 30 cents.

• Ask your child how much money you can save with two or three 20-cent coupons. Show him the other coupons and ask him how much money could be saved with each one. Have him write the amounts and then add them to show how much could be saved if all the coupons were used.

Weighing In
Grades 3-4

		In many schools, children learn the metric system of meters, grams and liters, along with the more familiar system of feet, ounces and gallons. Practicing measurement both ways helps children learn both systems.

Grocery shopping offers opportunities for children to increase their estimation and measurement skills by choosing and weighing fruit and vegetables.

What You Need

• A grocery scale

What to Do

• In the produce section of the store, explain to your child that what you pay for fruit and vegetables is based, in large part, on the quantity you buy and what it weighs—that produce is usually sold for a certain amount per pound. Tell her that pounds are divided into smaller parts called ounces, and it takes 16 ounces to make one pound. Show her the scale that is used to weigh produce.

• Gather the produce you want to buy and ask your child to weigh a few items. Then have her estimate the weight of another item before she weighs it. If you need one pound of apples, ask her to place several apples on the scale and then estimate how many apples she will have to add or take away to make one pound.

• Let your child choose two pieces of fruit, such as oranges. Have her hold one piece in each hand and guess which weighs more. Then have her use the scale to see if she is right.

• Ask your child questions such as the following to encourage her to think about measurement and estimation:

  • Will six potatoes weigh more or less than the six oranges?
  • Which has more potatoes, a pound of big ones or a pound of little ones?
  • How much do potatoes cost for each pound? If they cost 10 cents per pound, what is the total cost of the six potatoes?

• If your child knows the metric system (and the scale has a metric range), have her weigh items in grams and kilograms. Ask her to find out the following:

  • How a kilogram compares to a pound.
  • How many grams an apple weighs.
  • How many kilograms (or kilograms plus grams) a sack of potatoes weighs.
  • Which contains more apples, one pound or one kilogram?
  • Which weighs more, one pound apples or one kilogram of apples?

Check It Out
Grades 3-4

		Grocery shopping can be a good place to show children a practical use for calculators—for example, as a way to keep a running total of what the groceries cost.

The checkout lane of a grocery store can be a good place for children to practice using mental math by estimating the cost of groceries and figuring out change.

What to Do

• As you wait in a grocery checkout lane, use the time to have your child estimate what the total cost of your groceries will be. Tell him that one easy way to estimate a total is to round off numbers. That is, if an item cost 98 cents, round it off to $1. Explain that the answer he gets won't be the exact cost, but it will be about that. Tell him that the word about shows that the amount you say is just an estimate.

• Using the estimated total, ask your child: "If the groceries cost $16 and I have a $20 bill, how much change should the checker give back to me? If the cost is $17.25, what coins is she likely to give me?

• At the checkout counter, ask your child to watch as the items are rung up. What's the actual total cost of the groceries? How does this amount compare to the estimate? When you pay for the items, will you get change back from your $20 bill, or will you have to give the checker more money?

• If you receive change, have your child count it to make sure the amount is correct.

Put It Away
Grades 1-5

		Children can often make up very creative rules for classifying things. Don't be surprised if you have trouble guessing your child's rule!

Putting away groceries helps children develop classifying and mathematical reasoning skills and the ability to analyze data.

What You Need

• Groceries

What to Do

• Make a game out of putting away groceries. As you empty the bags, group the items according to some common feature. You might, for example, put together all the items that go in the refrigerator or all the items in cans.

• Tell your child that you're going to play "Guess My Rule." Explain that in this game, you sort the items and she has to guess what rule you used for grouping the items.

• After your child catches on to the game, reverse roles and ask her to use another "rule" to group these same items. She might, for example, group the refrigerator items into those that are in glass bottles or jars and those in other kinds of packaging. She might group the cans into those with vegetables, those with fruit and those with soup. When she's regrouped the items, guess what rule she used.