Counting and Numbers Summary

Arithmetic · Axiom Academy

SUMMARY Counting and Numbers Summary A recap of Unit 1 — how we count, name, compare, and group numbers. Numbers have order — each number is exactly one more than the number before it. Counting measures quantity — matching objects one-to-one tells you "how many," and the last number you say is the total. Numbers can be compared — we can always tell which is greater, which is less, or whether they are equal. Patterns make counting faster — skip counting jumps by a fixed step instead of counting by ones. Position carries value — a digit means something different in the ones place than in the tens place. Core Concept Counting & Number Names We learned to count forward from 1 to 20 and beyond, and to connect each spoken number to its written numeral and its name — recognizing, for example, that the numeral 7 is read "seven." Key idea: the counting sequence is always the same order. Watch out for: skipping or repeating a number — count each thing exactly once. Core Concept One-to-One & Cardinality A number tells you a quantity . By touching each object as you say one number — one-to-one matching — the very last number you say is how many there are in total. When to use: any time you need "how many" in a group. Watch out for: the last word counted is the answer — you don't recount. Core Concept Comparing Numbers

This is the written version of the interactive lesson above. See the full Arithmetic course.