This short video and interactive assessment activity is designed to teach third graders about solving for elapsed time in a sequence of events - word problems.

This task uses language, "half of the stamps," that students in Grade 5 will come to associate with multiplication by the fraction 12. In Grade 3, many students will understand half of 120 to mean the number obtained by dividing 120 by 2. For students who are unfamiliar with this language the task provides a preparation for the later understanding that a fraction of a quantity is that fraction times the quantity.

This short video and interactive assessment activity is designed to teach fifth graders about subtracting mixed numbers with different denominators.

This short video and interactive assessment activity is designed to teach second graders an overview of subtraction (numbers to 100).

This short video and interactive assessment activity is designed to teach second graders about subtracting 3 numbers - word problems.

This short video and interactive assessment activity is designed to teach fifth graders about adding fractions with common denominators.

This short video and interactive assessment activity is designed to teach fifth graders about subtracting fractions with different denominators.

This short video and interactive assessment activity is designed to teach fifth graders about subtracting mixed numbers with common denominators.

This short video and interactive assessment activity is designed to teach second graders about subtracting one-digit numbers - word problems.

This short video and interactive assessment activity is designed to teach second graders an overview of subtraction (numbers up to 20).

This short video and interactive assessment activity is designed to teach fourth graders about subtraction: completing the subtraction sentence.

This short video and interactive assessment activity is designed to teach third graders about subtraction: completing the subtraction sentence.

This is a video and interactive assessment activity designed to help first graders learn about subtraction word problems up to twenty.

This video and accompanying interactive assessment practice was designed to teach Two-step Subtraction (Numbers to 100) - Word Problems to first graders.

This short video and interactive assessment activity is designed to teach second graders an overview of subtraction (numbers up to 10).

This short video and interactive assessment activity is designed to teach second graders about subtracting by counting backward with pictures.

This course features a video review and an assessment practice of subtracting by crossing out with pictures for word problems. It is aimed at first grade math students.

This task provides a familiar context allowing students to visualize multiplication of a fraction by a whole number. This task could form part of a very rich activity which includes studying soda can labels.

This short video and interactive assessment activity is designed to give fourth graders an overview of addition (sums to 1,000).