Play select games from the ST Math second grade curriculum. Concepts include place value, number line, comparing numbers, and more.

## Place Value Petals

Model 3-digit numbers using visual place value representations.
• Use a visual base ten model to represent 3-digit numbers with hundreds (bouquets), tens (flowers), and ones (petals).
• Apply the idea that a set of 10-ones or tens makes 1 set of the next higher unit.
• Levels begin by matching the visual model to base-10 numbers (1, 10, 100), then progress to modeling 3-digit numbers with visuals.

## Number Line to 100

Estimate points on number lines up to 100 using benchmarks.
• Develop estimation strategies for finding numbers to 100 using benchmarks.
• Levels begin with number lines to 20, then progress to number lines to 100 with 0, 50, and 100 as benchmarks.
• Feedback allows students to revise their estimates based on initial responses.

## Two-Step Problem Solving

Use addition and subtraction strategies to solve 2-step problems.
• Develop strategies for solving multi-step problems using addition and subtraction.
• Find the exact number of pies that the ‘Pie Monsters’ need by adding or subtracting from the given pies on the table.
• Levels begin by feeding 1 monster visual pies, then move to feeding 2 monsters with numbers representing pies.

## Measuring Length

Develop concepts of measuring length in non-standard and standard units.
• Understand length as distance measured by iterating units without gaps or overlaps.
• Levels begin with non-standard, visual objects placed side-by-side, then progress to using rulers to measure distance.
• Feedback allows students to revise their estimates based on initial responses.

## Unknowns in Addition and Subtraction Situations

Find unknown numbers for addition or subtraction equations using visual models.
• Fill in the missing number to make an equation true using a visual model for adding or subtracting one- and two-digit numbers.
• Levels begin with finding sums or differences, then move to finding missing addends or subtrahends.
• Equations are posed with operation on either side of the equal sign: 24-3= 21 and 21=24-3.

## More Than, Less Than Comparing

Compare two whole numbers and find the difference.
• Develop the concept and language for comparing two whole numbers by finding the difference as ’more than’ or ‘less than’.
• Levels begin with visual models with differences of 2 to 4 blocks, then advance to comparing whole numbers: e.g, ‘3 is 2 less than 5’.
• Feedback allows students to understand the language and concept of comparing as addition or subtraction.