Thousands of Miles and Seats

Addition, Subtraction, and Number System

What is it all about?

This unit takes addition and subtraction one step farther. Now you are adding and subtracting in the thousands and tens of thousands. We will be solidifying our knowledge of place-value. Like I always say though, if you can add and subtract between the numbers 1 and 10 you can add and subtract anything. Thats why its called a base 10 number system.


Here are some pictures of place value.

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Place Value

Below are some videos to remind you all about place value. For something a little extra go to my main math page and watch the video on "The Dawn of Numbers"


Place Value to Millions
Base 10 Number System

Addition !

Number Line

Using the number-line for addition with ages 8-9

Algorithm

Addition 4

Subtraction

Counting Back

Subtraction: Using A Number Line

Counting Up

Subtraction - Part 2 - Counting On Using A Number Line

Regrouping

Subtraction With Regrouping Across Zero

How addition and subtraction are related.

Warning!

If you dont think you are quite ready for this video, wait. If you watch it and you are confused please come talk to me or send me a post or email! Good luck!


The relationship between Addition and Subtraction