Compare stories ask “How many more?” or “How many fewer?” In Kindergarten you matched groups. Here you also need parts and wholes and missing numbers.
Key idea
“How many more?” and “How many fewer?” both ask for the difference: the extra ones with no partner.
Why it works
When the groups are matched one to one, the matched ones are the same in both. Only the extras show how many more.
Worked example: How many more?
Ann has 9 shells. Ben has 5. How many more shells does Ann have?
- Match 5 of Ann’s shells with Ben’s 5.
- Ann has 4 extra.
- $5 + \square = 9$, so 4.
Answer: 4 more
Worked example: Fewer, but who has more?
Ben has 3 fewer cars than Ann. Ben has 6 cars. How many cars does Ann have?
- “Fewer” is about Ben, so Ann has more.
- Ann has 3 more than Ben: $6 + 3 = 9$.
Answer: 9 cars
Common mistake
Seeing the word “more” and adding: $9 + 5 = 14$. But “how many more” asks for the difference. Check: Ann has only 9 shells, so she can’t have 14 more!
For grown-ups: Compare real things: “You have 7 grapes and I have 4. How many more do you have?” Line them up to check.