Reasoning & explaining (MP2, MP3)

Helping Students Debrief

Mark Driscoll provides practical advice on building students' habits of reasoning by structuring discussions using particular questions and written tools.


FEATURING: Mark J. Driscoll, Education Development Center

SOURCE: Doing What Works

Developing Proportional Reasoning

This multimedia overview offers an introduction to students’ development of proportional thinking and its relationship to cross-multiplication. It describes recommended instructional strategies for solving problems related to ratio, rate, and proportion, including buildup and unit ratio strategies, and illustrates examples of real-world context for such problems. This recommended practice contains three tools to support the teaching and learning of ratio, rate, and proportion.


SOURCE:  Doing What Works

Cross Multiply? Not So Fast

Eighth-grade co-teachers lead a class through activities involving ratios. Students use concrete materials, build-up strategies, and cross-multiplication to solve the real-world problems found in Ratio: Warm Up Activity, Build-Up Strategies Worksheet, and Build a Cafe: PowerPoint and Report.


FEATURING: James Ro and Jackie Price, Howard County Public Schools (MD)

SOURCE: Doing What Works

Representing a Problem Visually

See how different groups of students use double number lines and other visuals to tackle "Frank's Problem," which involves figuring out the most efficient travel routes in terms of mileage.


FEATURING: John Corigliano, Fifth-Grade Teacher, Madison Elementary School (WA)

SOURCE: Doing What Works

Ways to Measure One and a Half Cups

A fourth-grade teacher asks students to help solve his problem of measuring 1-1/2 cups without either a 1-cup or a 1/2-cup measuring cup, and instead with the use of many other size measuring cups. Students write number sentences to describe the results of their measurement exploration.

FEATURING: Keith Phelps, Fourth-Grade Teacher, Eliza Hart Spalding School of Math and Technology (ID)

SOURCE: Doing What Works