Maya has $0.75. She earns $0.40 doing chores. How much does she have now? Which operation should you use?
ASubtraction — she used effort to earn the money, so some is spent
BAddition — money is coming in, so the total increases
CMultiplication — she might do chores multiple times
DDivision — the earnings should be split between savings and spending
The word 'earns' signals that money is being received — the total goes up. The correct operation is addition: $0.75 + $0.40 = $1.15. The key step is identifying the action in the story: earning/receiving/getting → add; spending/buying/paying → subtract. Option A is a classic confusion between the effort described in the story and the mathematical direction of the money.
Question 2 Multiple Choice
Tom has $1.00. He buys a sticker for $0.35 and a bookmark for $0.40. A student writes $1.00 + $0.35 + $0.40 = $1.75 and says Tom now has $1.75. What error did the student make?
AUsed the wrong operation — Tom is spending money, so the costs should be subtracted from his starting amount, not added
BAdded the numbers in the wrong order
CMade an arithmetic mistake (the correct sum is $1.65, not $1.75)
DForgot to include the $1.00 starting amount
The story says Tom is buying things — money is going out. The correct approach is to find the total cost ($0.35 + $0.40 = $0.75) and then subtract it from the starting amount ($1.00 − $0.75 = $0.25). Adding the prices to the starting amount instead of subtracting them is the most common operation-choice error in money word problems. A reasonableness check — 'Can buying things make you richer?' — immediately flags this as wrong.
Question 3 True / False
If you start a money word problem with $2.00 and the story says you spent some money, but your answer comes out to $2.50, something has gone wrong.
TTrue
FFalse
Answer: True
Spending money reduces your total — you cannot end up with more than you started with. An answer of $2.50 when you started with $2.00 and spent money is a clear sign you added when you should have subtracted. Checking reasonableness — asking 'Does this answer make sense given the story?' — is as important as the arithmetic itself.
Question 4 True / False
The words 'earns,' 'receives,' and 'gets' in a money word problem usually signal that you should subtract.
TTrue
FFalse
Answer: False
These words signal addition — money is coming in. Words that signal subtraction are 'spends,' 'buys,' 'pays,' and 'costs.' Mixing these up is the most common operation-selection error. Building a habit of identifying the action word before choosing an operation helps prevent this mistake.
Question 5 Short Answer
What two questions should you ask before doing any calculation in a money word problem, and why do they help?
Think about your answer, then reveal below.
Model answer: 'What do I know?' (identifying the given amounts) and 'What am I trying to find?' (identifying the unknown). These questions help because they force you to read the problem carefully, separate the relevant numbers from the story details, and identify whether the situation involves money coming in (add) or going out (subtract) — before you pick up a pencil to calculate.
Many errors in word problems come from jumping straight to calculation without understanding the situation. Asking these two questions creates a brief planning pause that connects the math to the real-world story, helping students choose the right operation and avoid treating all numbers in a problem as things to be added together.