Addition & subtraction strategies to solve two-digit equations using an open number line. In this lesson, students go over using different addition and subtraction strategies to solve two-digit ...

A key part—though surely not the only part—of early-grades math is ensuring students get the basic arithmetic functions down and, beyond that, making sure they’re able to swiftly and automatically ...

Time to test your brain! Are you a puzzle person? Most of these hard math problems aren’t straightforward arithmetic. They challenge you to look at problems a different way, testing your logic and ...

The basic building blocks of the whole numbers remain mysterious.

For all of the recent strides we’ve made in the math world—like a supercomputer finally solving the Sum of Three Cubes problem that puzzled mathematicians for 65 years—we’re forever crunching ...

In new research, mathematicians have narrowed down one of the biggest outstanding problems in math. Huge breakthroughs in math and science are usually the work of many people over many years. Seven ...

Measure your hand. Create and use a line plot of hand span data to answer questions. Warm up with a Mystery Math Mistake to find the mistake made in counting up on a number line to subtract. Notice ...

Thousands of computers across the world are currently scouring the number line in a scavenger hunt for rare mathematical gems. Enthusiasts looking for larger and larger prime numbers, which are ...