# Shopping bags

After you and your child get home from a trip to the supermarket, have them test the mass of the bags to determine which is the lightest by holding one in each hand. Comparing the weight of objects in this way is called 'hefting'.

### Things you need

• Grocery bag after a shop.

## The challenge

### Step 1

Let your child choose the bags they would like to test.

### Step 2

Ask your child to hold one bag in each hand and lift them up to feel which one is heavier or lighter.

### Step 3

Repeat this with all of the bags, and order them from the lightest to the heaviest.

### The conversation

• Have your child take an item of out of the bag of groceries. For example, a tin of tomatoes or a box of cereal, and try to find other items that have a similar mass.
• Draw your child's attention to the idea that sometimes smaller objects can be heavier than bigger objects. For example, a jar of jam might have a greater mass than a box of tissues.
• You could do the same activity using your child's toys or other household items.