Activity
Teachnology

Teachnology: Arithmetic Theme

For Teachers Pre-K - 1st Standards
Arithmetic Theme provides an excellent collection of free sample worksheets, teacher resources, lesson plans and interactive media to support addition, subtraction, multiplication and division.
Activity
Teachnology

Teachnology: Arithmetic Theme

For Teachers Pre-K - 1st Standards
Arithmetic Theme provides an excellent collection of free sample worksheets, teacher resources, lesson plans and interactive media to support addition, subtraction, multiplication and division.
Activity
University of Waterloo (Canada)

University of Waterloo: Arithmagic: Mental Math

For Students Pre-K - 1st Standards
Test your mental math skills in arithmetic. How many questions can you answer in one minute? Good luck!
Interactive
Educaplus (Jesús Peñas Cano)

Educaplus: Puzzle Algebraico

For Students 3rd - 5th
In this activity you can practice mental math by finding the value of each of the objects with the help of the given pictures.
Interactive
Other

P.u.e.m.a.c.: Juegos

For Students 9th - 10th
Try these interactive math games to test and train the mind. Good explanation is given for each of the games. Requires Java.
Activity
AAA Math

Aaa Math: Mentally Adding Two Digit Numbers

For Students 3rd - 8th
This site explains how to mentally add two-digit numbers. Gives exercises and games to practice this skill.
Activity
National Council of Teachers of Mathematics

The Math Forum: K 12 Math Problems, Puzzles, Tips & Tricks

For Students K - 1st
At this site us these tips & tricks to help students become better mental mathematicians.
Activity
Can Teach

Can Teach: Who Has More or Less?

For Teachers 2nd - 4th
Want to practice addition and subtraction skills in a new and exciting way? Use this online math lesson card game activity.
Interactive
AAA Math

Aaa Math: Adding Tens

For Students K - 1st Standards
This game helps you practice adding tens. You will get to see a percent score of the answers you have correct, as well as running totals of the answers you have correct and incorrect.