WA.4.1. Core Content: Multi-digit multiplication (Numbers, Operations, Algebra) Students learn basic multiplication facts and efficient procedures for multiplying two- and three-digit numbers. They explore the relationship between multiplication and division as they learn related division and multiplication facts in the same fact family. These skills, along with mental math and estimation, allow students to solve problems that call for multiplication. Building on an understanding of how multiplication and division relate to each other, students prepare to learn efficient procedures for division, which will be developed in fifth grade. Multiplication of whole numbers is not only a basic skill, it is also closely connected to Core Content in this grade level on area, and this connection reinforces understanding of both concepts. Multiplication is also central to students' study of many other topics in mathematics across the grades, including fractions, volume, and algebra.
4.1.I. Solve single- and multi-step word problems involving multi-digit multiplication and verify the solutions.
4.1.J. Solve single- and multi-step word problems involving division and verify the solutions.
WA.4.4. Additional Key Content (Geometry/Measurement, Algebra, Data/Statistics/Probability) Students use coordinate grids to connect numbers to basic ideas in algebra and geometry. This connection between algebra and geometry runs throughout advanced mathematics and allows students to use tools from one branch of mathematics to solve problems related to another branch. Students also extend and reinforce their work with whole numbers and fractions to describe sets of data and find simple probabilities. Students combine measurement work with their developing ideas about multiplication and division as they do basic measurement conversions. They begin to use algebraic notation while solving problems in preparation for formalizing algebraic thinking in later grades.
4.4.A. Represent an unknown quantity in simple expressions, equations, and inequalities using letters, boxes, and other symbols.