All About Numbers
Before, After and Between – Ordering Numbers in Sequence
Once counting feels natural, the next step is understanding a number's exact position relative to its neighbours – what comes right before it, right after it, or fits between two other numbers. Mathematicians call this sense of position ordinality, distinct from cardinality (knowing how many). A child can know that a set has “7” things in it (cardinality) without yet being confident that 7 sits right after 6 and right before 8 (ordinality) – both skills matter, and they usually develop together.
What Comes Before?
The number before any number n is always n minus one – one step back in the counting sequence.
What number comes right before 10?
Stepping back one from 10 gives 9.
What Comes Between?
What number comes between 5 and 7?
Counting from 5 to 7: 5, 6, 7.
Real-Life Application
- Reading page numbers: knowing what page comes next.
- Queueing: understanding who is in front of and behind you.
- Calendars: what day falls between Monday and Wednesday.
Key Takeaways
- Ordinality is understanding a number's position relative to its neighbours – distinct from cardinality (knowing “how many”).
- The number before n is n − 1; the number after n is n + 1.
- Solid number-order sense is essential before moving on to number bonds and addition.
Practice: Before, After and Between
What Comes Before?