Subtraction word problems describe situations where quantities are taken away, compared, or unknown. Solving them involves understanding the context, choosing subtraction, calculating the answer, and verifying reasonableness.
Use stories and contexts familiar to 2nd graders (sharing snacks, losing toys). Draw pictures to show what's happening. Use manipulatives to act out the problem before solving it abstractly.
A word problem is not a calculation dressed up in words — it is a small story about a situation, and your job is to understand the situation before you do any math. You already know how to subtract numbers within 100, so the new skill here is reading a problem and deciding *why* subtraction is the right operation. There are three main types of subtraction situations, and each one tells a different kind of story.
The first type is take away: you start with some amount, remove part of it, and want to know what is left. "Maria had 34 stickers. She gave 15 to her friend. How many does she have left?" This is the most familiar type. The second type is comparison: two quantities exist side by side and you want to know the difference. "Jake has 28 crayons. His sister has 17. How many more does Jake have?" No one is taking anything away — you are measuring a gap. The third type involves a missing part: you know the total and one part, and must find the other. "There are 40 students in the gym. 18 are playing basketball. The rest are reading. How many are reading?" These all require subtraction even though they sound different.
The key habit is to act out or draw the problem before writing a number sentence. Use counters, draw a picture, or sketch a bar model. What is the whole? What is the known part? What is the unknown? Once you can see the structure, the calculation is obvious. Students who rush to numbers first often subtract in the wrong direction or use addition when subtraction is needed — because they are guessing at the operation instead of reasoning about the story.
After you compute, always ask: does this answer make sense? If Maria started with 34 stickers and gave some away, her answer should be less than 34. If your calculator says 52, something went wrong. This reasonableness check is not optional — it is how mathematicians and engineers catch errors before they cause problems. Training yourself to verify your answers now builds a habit that will serve you through long division, algebra, and beyond.