Solved Exercises on Shopping Math in Grade 2

Master shopping math concepts: calculating prices, comparing costs, solving purchase-related word problems through these 5 detailed exercises.

Solution: Exercises 1 to 3
1 Item Pricing
Exercise 1
A toy car costs $8. If you buy 3 toy cars, how much do you spend in total?
Definition:

Total cost: The amount spent when buying multiple items

Multiplication method:
  1. Identify the price of one item
  2. Identify the number of items
  3. Multiply price by quantity
Price per Car
$8
Number of Cars
3
Total Cost
$8 × 3 = $24
Step 1: Identify the price of one item

Each toy car costs $8

Step 2: Identify the number of items

You want to buy 3 toy cars

Step 3: Calculate total cost

$8 per car × 3 cars = $24

Total cost is $24
Final answer:

You spend $24 in total for 3 toy cars

Applied rules:

• Multiplication: Price × Quantity = Total Cost

• Equal items: Same price for each item

• Total calculation: Add up all individual costs

2 Comparing Prices
Exercise 2
Store A sells a bike for $50. Store B sells the same bike for $45. How much cheaper is Store B?
Definition:

Price difference: The amount saved when choosing the cheaper option

Store A Price
$50
Store B Price
$45
Difference
$50 - $45 = $5
Step 1: Identify both prices

Store A: $50, Store B: $45

Step 2: Subtract the lower price from the higher price

$50 - $45 = $5

Step 3: State the savings

Store B is $5 cheaper

Store B is $5 cheaper
Final answer:

Store B is $5 cheaper than Store A

Applied rules:

• Comparison: Higher price - Lower price = Difference

• Subtraction: Calculate the difference

• Savings: The amount you save by choosing the cheaper option

3 Budget Planning
Exercise 3
Emma has $20. She wants to buy a book for $7 and a pencil for $3. How much money will she have left?
Definition:

Money left: The remaining amount after purchases

Starting Money
$20
Total Cost
$7 + $3 = $10
Money Left
$20 - $10 = $10
Step 1: Identify starting amount

Emma has $20

Step 2: Calculate total cost of purchases

Book: $7 + Pencil: $3 = $10 total

Step 3: Subtract total cost from starting amount

$20 - $10 = $10 left

Emma has $10 left
Final answer:

Emma will have $10 left after her purchases

Applied rules:

• Budget calculation: Starting money - Total expenses = Money left

• Addition: Sum all purchase costs

• Subtraction: Deduct expenses from available funds

Shopping Math Facts
Total Cost = Price × Quantity
Multiplication Formula
Shopping Math
Total = Price × Quantity
Price Difference = Higher - Lower
Money Facts
$1.00 = 100¢
Quarter = 25¢
Budget Math
Money Left = Starting - Expenses
Money Needed = Goal - Current
Key definitions:

Price: How much something costs

Quantity: How many items you buy

Total cost: The full amount you pay

Complete methodology:
  1. Read the problem: Identify what's given and what's needed
  2. Identify variables: Find prices, quantities, and amounts
  3. Choose operation: Multiplication for totals, subtraction for differences
  4. Calculate: Perform the math operation
  5. Check: Make sure answer makes sense
Tip 1: Remember: Total = Price × Quantity, always multiply for multiple items.
Tip 2: When comparing prices, subtract the lower from the higher.
Tip 3: Always add up all costs before subtracting from your money.
Tip 4: Practice with real store scenarios to build skills.
Common errors: Forgetting to multiply for multiple items, subtracting in wrong order for price comparisons.
Practice tips: Use real store flyers, practice with play money, simulate shopping trips.
Formulas to know by heart:

• Total Cost = Price × Quantity

• Price Difference = Higher Price - Lower Price

• Money Left = Starting Money - Total Expenses

• $1.00 = 100¢

• Quarter = 25¢, Dime = 10¢, Nickel = 5¢, Penny = 1¢

Solution: Exercises 4 to 5
4 Multiple Items
Exercise 4
Tom buys 2 books at $6 each and 3 pens at $2 each. What is his total cost?
Definition:

Multiple purchases: Calculating cost for different types of items

Books Cost
2 × $6 = $12
Pens Cost
3 × $2 = $6
Total Cost
$12 + $6 = $18
Step 1: Calculate cost of books

2 books × $6 each = $12

Step 2: Calculate cost of pens

3 pens × $2 each = $6

Step 3: Add both amounts

$12 + $6 = $18 total

Total cost is $18
Final answer:

Tom's total cost is $18

Applied rules:

• Separate calculations: Calculate each item type separately

• Addition: Sum all individual costs

• Multiplication: Price × Quantity for each item

5 Shopping Decision
Exercise 5
Lisa has $30. She wants to buy a dress for $18 and shoes for $15. Does she have enough money? If not, how much more does she need?
Definition:

Budget check: Determining if you have enough money for purchases

Available Money
$30
Total Cost
$18 + $15 = $33
Money Needed
$33 - $30 = $3
Step 1: Calculate total cost of purchases

Dress: $18 + Shoes: $15 = $33

Step 2: Compare with available money

Needed: $33 vs Available: $30

Step 3: Calculate shortfall

$33 - $30 = $3 more needed

Step 4: State the conclusion

Lisa needs $3 more to buy both items

Lisa needs $3 more
Final answer:

Lisa does not have enough money. She needs $3 more to buy both items.

Applied rules:

• Comparison: Total needed vs Money available

• Shortfall calculation: Difference when needed > available

• Budget planning: Assess affordability before purchasing

Detailed Summary: Shopping Math
Complete Learning Summary
Key Concepts & Definitions

Price: How much something costs

Quantity: How many items you buy

Total cost: The full amount you pay

Budget: The money you have available to spend

Price comparison: Looking at different prices to find the best deal

Core Rules & Principles

• Total Cost Formula: Total = Price × Quantity

• Price Difference: Higher Price - Lower Price

• Budget Check: Money Available - Total Cost = Money Left (or Shortfall)

• Multiplication: Price × Quantity = Payment

• Money Conversion: $1.00 = 100¢

Step-by-Step Method

1. Identify: Find the given information (prices, quantities, budget)

2. Plan: Decide which formula to use

3. Calculate: Perform the necessary math operations

4. Compare: Check if you have enough money

5. Verify: Check that your answer makes sense

Examples & Applications

Simple Example: $5/item × 2 items = $10 total

Medium Example: Store A: $10, Store B: $8 → Difference: $2

Complex Example: 3 items at $4 each = $12 total

Real World: Planning shopping trips, comparing prices, budgeting

Tips & Tricks

• Remember: Total = Price × Quantity, always multiply for multiple items

• Compare Prices: Look for the lowest price to save money

• Estimate First: Get a rough idea before calculating

• Check Your Work: Always verify your answer makes sense

• Practice Regularly: Use real store scenarios to build skills

Memory Aids

• Price Rhyme: "Price times quantity gives total, that's the way to calculate!"

• Comparison Rhyme: "Higher minus lower gives the difference, that's how price comparison works!"

• Visual: Think of a shopping cart filling up with items

• Memory Trick: "P × Q = T" (Price × Quantity = Total)

• Key Words: "each" means multiply by the number of items

Tip 1: Always write down the formula before solving: Total = Price × Quantity.
Tip 2: Add up all costs before comparing with your budget.
Tip 3: When comparing prices, subtract the lower from the higher.
Tip 4: Practice with different prices to build fluency.
Common errors: Forgetting to multiply for multiple items, subtracting in wrong order for price comparisons.
Success strategies: Draw pictures of items, use play money to practice, check calculations twice.
Essential Formulas:

• Total Cost = Price × Quantity

• Price Difference = Higher Price - Lower Price

• Money Left = Starting Money - Total Expenses

• Money Needed = Total Cost - Available Money

• $1.00 = 100¢, Quarter = 25¢, Dime = 10¢, Nickel = 5¢, Penny = 1¢

Questions & Answers

Question: I don't understand how to calculate the total when I'm buying different kinds of things. Can you explain?

Answer: When buying different kinds of things, calculate each type separately, then add them together:

  • Calculate the cost for each type of item
  • Add all the individual costs together

Example: 2 books at $4 each AND 3 pencils at $1 each

Step 1: Books cost = 2 × $4 = $8

Step 2: Pencils cost = 3 × $1 = $3

Step 3: Total = $8 + $3 = $11

So the total cost is $11.

Always multiply within each group first, then add the groups!

Question: How do I know if I have enough money for my purchases?

Answer: To check if you have enough money, follow these steps:

Steps to follow:

  • Calculate the total cost of all items you want to buy
  • Compare this total with the money you have
  • If your money is equal to or greater than the total, you have enough
  • If your money is less than the total, you need more

Example: You have $20 and want to buy items costing $15 total:

$20 (available) > $15 (needed), so you have enough

You'll have $20 - $15 = $5 left over

If you only had $10, you'd need $15 - $10 = $5 more

Question: How can I check if my shopping math is correct?

Answer: Here are several ways to check your shopping math:

For total cost calculations:

  • Check: Price × Quantity = Total
  • Example: $3 × 4 items = $12
  • Check backwards: $12 ÷ 4 items = $3 per item

For budget checks:

  • Add up your purchases to see if they match the total
  • Estimate first: Does the answer seem reasonable?
  • Check that your money amount makes sense

Other verification tips:

  • Make sure units match (dollars with dollars)
  • Check that your answer makes sense in the real world
  • Try solving the problem a different way to confirm

This checking technique helps catch common errors!