Grade 2 · Time & Money · MAT-02-MONEY-002
Solve Money Word Problems
Solve addition/subtraction problems involving cents and dollars.
Learning objectives
What you should be able to do
- Solve addition/subtraction problems involving cents and dollars.
- Find totals, differences, and simple change amounts.
- Write money units correctly and check answers for reasonableness.
Prerequisite check
Make sure the foundation is ready.
Checks value and word-problem foundations.
Learn
Build the idea from meaning, not memorization.
Money problems still use familiar structures
Buying, combining, and making change use join, separate, part-whole, and compare relationships. Identify the relationship before choosing an operation.
Keep monetary units visible
35¢+20¢=55¢. When dollars are used, write a dollar sign and two decimal places when appropriate, such as$1.25. At this level, simple cent totals should remain clear.
Change is a difference
If an item costs65¢ and you pay100¢, change is100−65=35¢. Addition can check it:65¢+35¢=100¢.
Estimate before calculating
If two prices are about40¢ each, their total should be near80¢. A result such as8¢ is unreasonable.
Interactive math lab
Change it. See what stays true.
Equation Balance
Adjust both sides. Equality means both expressions have the same value.
Balanced: both sides have equal value.
- total cost
- make change
- find needed
- check with coins
Worked examples
Twenty different ways to see the concept work.
25¢+30¢
55¢Combine costs.
60¢−20¢
40¢Difference/remain.
Item45¢ paid50¢
5¢ change50−45.
Item65¢ paid100¢
35¢ change100−65.
Two items25¢ each
50¢25+25.
35¢+42¢
77¢Add cents.
90¢−37¢
53¢Subtract.
Quarter+dime purchase total
35¢Coin values.
Spend28¢ from75¢
47¢ remain75−28.
Save40¢ then25¢
65¢Join.
Price55¢ vs43¢ difference
12¢55−43.
3 dimes+2 nickels value
40¢30+10.
Pay$1 for70¢ item
30¢ change100−70.
Two45¢ items
90¢45+45.
100¢ equals
$1.00Dollar-cent equivalence.
$1.00−25¢
75¢100−25.
Item30¢+tax-like extra5¢
35¢Join quantities.
Have80¢ need95¢. More needed?
15¢95−80.
Check65¢+35¢
100¢Confirms change.
Estimate48¢+31¢
about80¢Exact79¢.
Practice
Guided practice with hints
01Item38¢ paid50¢
Hint: Subtract price from paid.
Answer: 12¢
0227¢+35¢
Hint: Add cents.
Answer: 62¢
0390¢−45¢
Hint: Difference.
Answer: 45¢
04Have55¢ need70¢
Hint: Find gap.
Answer: 15¢
05$1 minus60¢
Hint: Think100 cents.
Answer: 40¢
06Why check change with addition?
Hint: Price+change should equal paid.
Answer: Confirms difference.
Practice
Independent practice
0125¢+45¢
Answer: 70¢
0280¢−26¢
Answer: 54¢
03Pay100¢ for73¢
Answer: 27¢
04Need90¢ have65¢
Answer: 25¢
0550¢+25¢
Answer: 75¢
06$1−40¢
Answer: 60¢
07Estimate39¢+42¢
Answer: about80¢
08Change means
Answer: Amount paid minus cost.
Common mistakes
Learn to catch the error, not just the answer.
Change is the difference between amount paid and cost.
Write cents or dollars with every result.
100 cents equals$1.
Applications & challenge
Use the idea beyond a single exercise.
Applications
- Calculate totals/change in pretend stores.
- Compare savings goals and amounts available.
Challenge problems
Two items total85¢; one is37¢. Other?
48¢
Have3 quarters; buy52¢ item. Change?
23¢
Why is100¢−99¢=1¢ reasonable?
99¢ is one cent less than a dollar.
Create two purchases totaling$1.
Any pair summing100¢.
Flashcards
Retrieve it from memory.
Flashcards
Card 1 of 6
Game mode
Mini Market
Buy items, total costs, and make exact change.
Practice
Mastery check
0134¢+25¢
Answer: 59¢
0290¢−38¢
Answer: 52¢
03Pay100¢ for64¢
Answer: 36¢
04Have48¢ need70¢
Answer: 22¢
05100¢ equals
Answer: $1
06How check change?
Answer: Add price and change.
07Estimate47¢+29¢
Answer: about80¢
08Why keep unit
Answer: It identifies monetary value.
Terminology
Words to know
- price
- The amount of money required to buy something.
- change
- Money returned when payment exceeds cost.
- total cost
- Combined price of purchases.
- dollar
- A unit equal to100 cents.
Continue learning
Connected concepts
Curriculum references
Standards and instructional references
California Common Core State Standards for Mathematics — 2.MD.C.8
Money word problems involving common denominations.