Overview from Everyday Mathematics
"One of the most important topics in mathematics is the study of patterns. Since patterns are predictable, it is usually possible to state a rule that describes each pattern. This rule can then be used to extend the pattern. Much of Unit 3 focuses on number patterns: odd and even numbers; patterns in number lines and number grids; and number sequences. Number patterns will be revisited throughout the year. This unit continues to steady development of some important fist grade topics: Telling time is extended to times on the half-hour, dimes are added to children's existing collections of coins to be counted, and work is begun on solving simple addition and subtraction problems."
Unit 3 has four main areas of focus: