**Number and Operations in Base Ten** |

**Abacus** |
An
electronic abacus that can be used to do arithmetic. |

**Base Blocks Addition** |
Use
base ten blocks to model grouping in addition. |

**Base Blocks Subtraction** |
Use
base ten blocks to model separation of groups in subtraction. |

**Base Blocks ** |
Illustrate addition and subtraction in a variety of bases. |

**
Bobbie Bear** |
Bobbie
Bear is planning a vacation and wants to know how many outfits
can be made using different colored shirts and pants. |

**Chip Abacus** |
Learn
about carrying and digits using chips. |

**Color Chips - Addition** |
Use
color chips to illustrate addition of integers. |

**Color Chips - Subtraction** |
Use
color chips to illustrate subtraction of integers. |

**
Concentration** |
By
yourself or against a friend, match whole numbers, shapes,
fractions, or multiplication facts to equivalent
representations. Practice with the clear panes or step up the
challenge with the windows closed. How many socks can you win? |

**Curious George: Glass Palace** |
Find
the next number in the sequence. |

**
Deep Sea Duel** |
Okta
challenges you to a duel! That crazy octopus wants to play you
in a game where the first person to choose cards with a
specified sum wins. You can choose how many cards, what types of
numbers, and Okta's level of strategy. |

**Dog Bone** |
Finding numbers from a number square. |

**
Five Frame** |
Thinking about numbers using frames of 5 can be a helpful way to
learn basic number facts. The four games that can be played with
this applet help to develop counting and addition skills. |

**Ghost Blasters** |
This game focuses on finding multiples of 10. |

**Ghost Blasters 2** |
This games lets you choose to practice sums of the number you
set |

**Ghost Blasters 3** |
This game is for practicing two digit plus one digit numbers. |

**Ghost Blasters **
**6** |
This game is for practicing 2 digit minus 1 digit subtraction. |

**Ghost Blasters Evens** |
Practice finding the even numbers |

**Ghost Blasters Odds** |
Practice finding the odd numbers |

**
Grouping and Grazing** |
Help the alien spaceship move cows into corrals by counting,
adding, and subtracting. This activity helps children learn
grouping, tally marks, and place value. As they master counting,
they can move on to adding and subtracting two-digit numbers. |

**
How Many Under the Shell?** |
After Okta hides some bubbles under a shell, he then either adds
more bubbles or takes some away. Students have to determine how
many bubbles are left under the shell. |

**Hundreds Chart** |
Practice counting and visualize number patterns using a hundreds
chart. |

**Math Magic** |
Timed practice of basic math facts in addition, subtraction,
multiplication and division |

**Math Magician** |
Practice Addition, Subtraction, Division, and Multiplication
facts by number |

**Number Line Arithmetic** |
Illustrates arithmetic operations using a number line. |

**Number Line Bounce** |
Number
line addition and subtraction game. |

**Number Patterns** |
Discover the pattern and complete a sequence of numbers. |

**
Okta's Rescue** |
Okta's
Rescue is lots of fun for kids! Plus they are using their
counting skills while playing! |

**Place Value Number Line** |
Explore place value by placing dots on number lines. |

**Speed Grid Addition 1** |
Addition Level 1 |

**Speed Grid Addition 2** |
Addition Level 2 |

**Speed Grid Addition 3** |
Addition Level 3 |

**Speed Grid Subtraction 1** |
Subtraction Level 1 |

**Speed Grid Subtraction 2** |
Subtraction Level 2 |

**Speed Grid Subtraction 3** |
Subtraction Level 3 |

**Splat Squares 0-100** |
Number square 0-100 |

**Splat Squares 0-99** |
Number square 0-99 |

**Splat Squares- Reveal 0-100** |
Blank number square 0-100 |

**Splat Squares Reveal 0-99** |
Blank number square 0-99 |

**
Ten Frame** |
Thinking about numbers using frames of 10 can be a helpful way
to learn basic number facts. The four games that can be played
with this applet help to develop counting and addition skills. |