CK-12 Foundation
Add and Subtract Decimals with Front-End Estimation: Wooden Beams
A six-question interactive tasks mathematicians to solve addition and subtraction problems using front-end estimation. Question types consist of multiple-choice and true or false. A set of wooden beams that can be measured using moveable...
CK-12 Foundation
Differences of Fractions with Different Denominators
Subtracting fractions with unlike denominators is the focus of an interactive designed to boost mathematicians' problem-solving skills. Five questions challenge participants to answer multiple-choice and true or false questions with help...
CK-12 Foundation
Expression Evaluation with Different Denominators: Adding Mixed Fractions of Water
An interactive challenges mathematicians to add mixed fractions with unlike denominators. Five questions—fill-in-the-blank and multiple-choice—build from one to the next leading the way to an open discussion about denominators and...
CK-12 Foundation
Whole Number Addition: Let's Go Fishing!
Practice adding whole numbers by combining the amount of fish Alice and Bob catch. As young mathematicians work through each problem, they are asked to find one more plus the amount of fish already caught. They can manipulate the...
CK-12 Foundation
Repeating Decimals: Does 1 equal 0.999... ?
Six questions make up a challenging interactive that tests scholars' knowledge of repeating decimals. Mathematicians answer true or false and multiple-choice questions with help from a tool that highlights decimal movement in an...
CK-12 Foundation
Horse and Cart
Can a horse pull more than its weight? A simple simulation answers this question and more. Pupils adjust the mass in a cart, the mass of the horse, the acceleration of the horse, and the angle of the tension rope between the horse and...