Link to MORE grade three math games compiled in Saskatchewan that match our curriculum! I will add these to the list below as soon as I get a chance. Thanks Andrea for finding these for us. CVdR
Strand: Number
General Outcome: 
Web Links  Overviews of Web Links 
A1 Say the number sequence forward and backward from 0 to 1000 by:

Interactive Calculator and Number Chart

Demonstrate number patterns using a calculator. Displays on a number chart up to 1000. 
A2 Represent and describe numbers to 1000 concretely, pictorially and symbolically.  Virtual Base Ten Blocks

Base ten blocks that can be manipulated and adjusted to cover thousands to thousandths 
A3 Compare and order numbers to 1000.  Compare and Order Numbers

Compare and order numbers. Can select to 1 000 up to 100 000 
A5 Illustrate, concretely and pictorially, the meaning of place value for numerals to 1000.  Place Value

Placing correct digits in place value spaces 
A6 Describe & apply mental mathematics strategies for adding two 2digit numerals such as:

Manipulative Base Ten/Tenth Blocks

Add and subtract using base interactive ten blocks  can be adjusted from thousands to thousandths 
A7 Describe & apply mental strategies for subtracting two 2digit numerals such as:

Manipulative Base Ten/Tenth Blocks

Add and subtract using base interactive ten blocks  can be adjusted from thousands to thousandths 
A8 Apply estimation strategies to predict sums and differences of two 2digit numerals in a problemsolving context.  Adding / Subtraction Estimation

Quick problem solving using estimation when adding and subtracting 
A9 Demonstrate an understanding of addition & subtraction of numbers with answers to 1000 (limited to 1, 2 and 3digit numerals) concretely, pictorially & symbolically by:

Speedy Sums

Challenging Adding game – recommended for later in year for primaries 
A10 Apply mental mathematics strategies and number properties, such as:

Adding Horizontally

Addition questions with three options to choose from 
Adding Vertically

Addition questions with three options to choose from  
Subtracting Vertically

Subtraction questions with three options to choose from  
A11 Demonstrate an understanding of multiplication to 5 ´ 5 by:

Multiplication Matching

Match multiplication questions to three options 
A13 Demonstrate an understanding of fractions (concretely, pictorially or symbolically) by:

Identifying Fractions

Identify fractions on a number line 
Strand: Statistics & Probability (Data Analysis)
General Outcome: 
Web Links  Overviews of Web Links 
D2 Construct, label and interpret bar graphs to solve problems.  Bar Graph Generator

Input data and bar graph will be created. 
Strand: Patterns & Relations (Patterns)
General Outcome: 
Web Links  Overviews of Web Links 
B1 Demonstrate an understanding of increasing patterns by:

Crack the Code

Finish the patterns to crack the code (numbers, shapes and/or colours. 
Finish the Pattern

Choose shape/letter/number that goes into the pattern 
Strand: Shape & Space (Measurement)
General Outcome: 
Web Links  Overviews of Web Links 
C1 Relate the passage of time to common activities using nonstandard and standard units (minutes, hours, days, weeks, months and years).  Times of the Day

Identify times on a clock with times during the day 
C2 Relate the number of seconds to a minute, the number of minutes to an hour and the number of days to a month in a problemsolving context.  Comparing Time

Compare minutes to hours in a day (3 Challenge Levels) 
C3 Demonstrate an understanding of measuring length (cm and m) by:

Comparing Length, Mass and Capacity

Converting mm to cm, m etc.. 
C4 Demonstrate an understanding of measuring mass (g and kg) by:

Animal See Saw

Compare animal weights on a scale (two players) 
Seesaw Logic

Use logic to determine the heavier item  
C5 Demonstrate an understanding of perimeter of regular and irregular shapes by:

Shape Generator

Creates random shapes. Asks for area and perimeter of the shape 
Strand: Shape & Space (3D Objects & 2D Shapes)
General Outcome: 
Web Links  Overviews of Web Links 
C7 Sort regular and irregular polygons, including:

Matching Shapes

Shape matching game 
Tangram Shape Generator

Tangram shape generator – develops spatial reasoning skills  
Shape Sort

Sort shapes into categories using Venn Diagrams 