Money choices, explained

Compare grocery unit prices, total a hypothetical basket, and identify the conditions attached to an advertised cost.

About 18 minutes

Read the example, try the task, then open the self-check. No purchase or AI generation required.

LESSON 01

Compare the same amount

Package prices are easier to compare when you convert them to the same quantity. For a price per 100 grams, divide the price by the package weight in grams, then multiply by 100. Keep the units visible. A lower unit price describes the cost of an equal amount; the larger package may still cost more at checkout or contain more than you need.

Calculate price per 100 grams by dividing price by weight, then multiplying by 100.
Compare unit price and checkout price separately, keeping the quantities and units visible.

A worked example

Hypothetical rice A costs $1.20 for 400 g: $1.20 ÷ 400 × 100 = $0.30 per 100 g. Rice B costs $1.80 for 750 g: $1.80 ÷ 750 × 100 = $0.24 per 100 g. B has the lower unit price; A has the lower package price.

Now you tryCompare oats at $2.00 for 500 g with oats at $3.00 for 1,000 g. Calculate each price per 100 g, then name the lower unit price and the lower checkout price.

Check your practice

$2 ÷ 500 × 100 = $0.40 per 100 g; $3 ÷ 1,000 × 100 = $0.30 per 100 g. The larger pack has the lower unit price; the smaller pack costs less at checkout.

LESSON 02

Build and check a basket total

A small spending plan is an arithmetic exercise: choose a starting amount, list the costs, add them, and subtract the total from the starting amount. Write money consistently with two decimal places so cents line up. Count repeated items separately or multiply their price by the quantity. These examples use invented prices and exclude taxes or fees unless they are explicitly listed.

Multiply repeated items by their quantity, then add every listed cost.
Subtract the basket total from your starting amount and keep cents aligned.

A worked example

With a hypothetical $10.00 limit, bread at $2.40, beans at $1.80, and fruit at $3.60 total $7.80. The amount left is $10.00 − $7.80 = $2.20.

Now you tryA sample basket has two yogurts at $0.75 each and a loaf at $2.50. Find the total and the amount left from $6.00. Show both the multiplication and subtraction.

Check your practice

2 × $0.75 = $1.50. $1.50 + $2.50 = $4.00. $6.00 − $4.00 = $2.00 left.

LESSON 03

Read the conditions beside the price

An advertised amount may depend on quantity, package size, or a condition printed nearby. Read the complete label before doing the arithmetic. Distinguish the price of one item from the amount payable for several items, and include any stated extra charge. When a condition is unclear, ask for clarification instead of assuming. Here, the goal is understanding the cost shown, not choosing a purchase.

Read quantity requirements and other conditions beside an advertised price.
Include stated extra charges and ask about unclear conditions before calculating the final amount.

A worked example

A hypothetical label says '3 cartons for $6.00; individual cartons $2.50.' Three cost $6.00, or $2.00 each. One costs $2.50. The three-item rate does not make a single carton cost $2.00.

Now you tryA sample order shows two items at $4.00 each plus a stated $2.00 delivery charge. Write the item subtotal, the delivery charge, and the final amount.

Check your practice

$4.00 × 2 = $8.00 in items. Add $2.00 delivery for a $10.00 final amount.

CHECK YOUR UNDERSTANDING

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Original Junction practice lessons, assisted by AI and reviewed for this page. Examples are illustrative. Self-reported progress is not a grade, certificate or professional qualification. External resources have their own terms.