Marjorie M. Petit has provided leadership in the development and ongoing implementation of the Ongoing Assessment Project (OGAP) and is a partner in OGAPMath LLC.Robert E. Laird is Co-director of Teaching, Learning, and Research for the Vermont Mathematics Institute (VMI), USA. Bob is a OGAP National Facilitator and a partner in OGAPMath LLC.Caroline B. Ebby is Senior Researcher at the Consortium for Policy Research in Education (CPRE) and Adjunct Associate Professor at the Graduate School of Education at the University of Pennsylvania, USA. Caroline is a National OGAP Facilitator.Edwin L. Marsden was Professor of Mathematics and Former Chair of the Department of Mathematics at Norwich University, USA.

• 1 Understanding Fractions as a Number 2 Developing Understanding of Fractions Through Visual Models 3 What is the Whole? 4 Equipartitioning 5 Understanding the OGAP Fraction Framework and Progression6 Using the OGAP Fraction Progression to Inform Instruction and Support Student Learning7 Equivalence8 Comparing and Ordering9 Number Lines and Fractions10 The Density of Fractions11 Addition and Subtraction of Fractions12 Multiplication and Division of Fractions

Marjorie M. Petit has provided leadership in the development and ongoing implementation of the Ongoing Assessment Project (OGAP) and is a partner in OGAPMath LLC.Robert E. Laird is Co-director of Teaching, Learning, and Research for the Vermont Mathematics Institute (VMI), USA. Bob is a OGAP National Facilitator and a partner in OGAPMath LLC.Caroline B. Ebby is Senior Researcher at the Consortium for Policy Research in Education (CPRE) and Adjunct Associate Professor at the Graduate School of Education at the University of Pennsylvania, USA. Caroline is a National OGAP Facilitator.Edwin L. Marsden was Professor of Mathematics and Former Chair of the Department of Mathematics at Norwich University, USA.

• 1 Understanding Fractions as a Number 2 Developing Understanding of Fractions Through Visual Models 3 What is the Whole? 4 Equipartitioning 5 Understanding the OGAP Fraction Framework and Progression6 Using the OGAP Fraction Progression to Inform Instruction and Support Student Learning7 Equivalence8 Comparing and Ordering9 Number Lines and Fractions10 The Density of Fractions11 Addition and Subtraction of Fractions12 Multiplication and Division of Fractions

Marjorie M. Petit has provided leadership in the development and ongoing implementation of the Ongoing Assessment Project (OGAP) and is a partner in OGAPMath LLC.Robert E. Laird is Co-director of Teaching, Learning, and Research for the Vermont Mathematics Institute (VMI), USA. Bob is a OGAP National Facilitator and a partner in OGAPMath LLC.Caroline B. Ebby is Senior Researcher at the Consortium for Policy Research in Education (CPRE) and Adjunct Associate Professor at the Graduate School of Education at the University of Pennsylvania, USA. Caroline is a National OGAP Facilitator.Edwin L. Marsden was Professor of Mathematics and Former Chair of the Department of Mathematics at Norwich University, USA.

• 1 Understanding Fractions as a Number 2 Developing Understanding of Fractions Through Visual Models 3 What is the Whole? 4 Equipartitioning 5 Understanding the OGAP Fraction Framework and Progression6 Using the OGAP Fraction Progression to Inform Instruction and Support Student Learning7 Equivalence8 Comparing and Ordering9 Number Lines and Fractions10 The Density of Fractions11 Addition and Subtraction of Fractions12 Multiplication and Division of Fractions