This short video and interactive assessment activity is designed to teach third graders about perimeter in grid.

This short video and interactive assessment activity is designed to teach third graders about perimeter of squares and rectangles.

This short video and interactive assessment activity is designed to teach second graders an overview of perimeter.

CK-12 Physical Science for Middle School FlexBook® covers core physical science concepts and includes SIMs, PLIX, real world examples, and videos.

A complete introduction to scientific investigation and the scope of physical science. Includes: states of matter, atoms, periodic table, chemical bonding, chemical reactions, carbon chemistry, chemistry of solutions, nuclear chemistry, motion, forces, Newton's Laws of Motion, work and machines, energy, waves, sound, electromagnetic radiation, visible light, electricity, and magnetism.

The CK-12 21st Century Physics FlexBook is a collaborative effort of the Secretaries of Education and Technology and the Department of Education that seeks to elevate the quality of physics instruction across the Commonwealth of Virginia.

This short video and interactive assessment activity is designed to teach fifth graders about adding, subtracting, multiplying and dividing - missing operation.

This short video and interactive assessment activity is designed to teach fourth graders about four operations - missing operation.

This short video and interactive assessment activity is designed to teach fourth graders about adding, subtracting, and multiplying with parentheses - missing operation.

This short video and interactive assessment activity is designed to teach fifth graders about adding and subtracting with parentheses ii.

This short video and interactive assessment activity is designed to teach fourth graders about placing the missing parentheses to make the equation true.

This short video and interactive assessment activity is designed to teach fifth graders about placing the missing parentheses to make the equation true.

This short video and interactive assessment activity is designed to give fourth graders an overview of - thousandths.

This short video and interactive assessment activity is designed to teach second graders an overview - thousandths.

This short video and interactive assessment activity is designed to teach fourth graders about using both division and multiplication - word problems.

This short video and interactive assessment activity is designed to teach third graders about finding the amount of change - multiplication.

This short video and interactive assessment activity is designed to teach third graders about place value problems involving money.

This short video and interactive assessment activity is designed to teach third graders about prime factorization.

CK-12 Foundation's new and improved Advanced Probability and Statistics-Second Edition FlexBook introduces students to basic topics in statistics and probability, but finishes with the rigorous topics an advanced placement course requires.