Topic 2 - Addition & Subtraction
Properties of Addition Find a Rule Write a Number Sentence
Mental Math Estimating Sums Estimating Differences
Relating Addition and Subtraction (Fact Families)
Vocabulary
Commutative Property of Addition- Numbers can be added in any order and the sum will be the same.
Identity Property of Addition - The sum of any number and zero is that same number.
Associative Property of Addition- The grouping of addends can be changed and the sum will be the same.
Addend:numbers added together to give a sum
Sum- the answer to an addition problem
Rounding- to replace a number with a number that tells about how much or how many to the nearest ten, hundred, thousand, and so on.
Estimate- to give an approximate number or answer.
Helpful Skill Links
Rounding Practice
Adding 2 1-Digit Numbers
Island Chase Subtraction Game
Adding Machine Game
Fact Family Game
Math Magician Game (addition)
In and Out Boxes Game(Find a Rule)
Estimation Contraption
Seashell Rounding
Cannon Math
Math Baseball- Facts Practice
Math Man
Stop the Monster- In & Out Boxes Game