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Math for Grade 2
1 Number Sense and Numeration
1-1 Counting
1-1 1 Count forward from any given number up to 100
1-1 2 Count backward from any given number within 100
1-2 Place Value
1-2 1 Understand the concept of tens and ones
1-2 2 Identify the place value of digits in two-digit numbers
1-3 Comparing Numbers
1-3 1 Compare two-digit numbers using symbols (<, >, =)
1-3 2 Order numbers from least to greatest and greatest to least
1-4 Rounding
1-4 1 Round numbers to the nearest ten
2 Addition and Subtraction
2-1 Basic Addition
2-1 1 Add two one-digit numbers
2-1 2 Add a one-digit number to a two-digit number
2-2 Basic Subtraction
2-2 1 Subtract two one-digit numbers
2-2 2 Subtract a one-digit number from a two-digit number
2-3 Addition and Subtraction Facts
2-3 1 Memorize addition facts for sums up to 20
2-3 2 Memorize subtraction facts for differences up to 20
2-4 Word Problems
2-4 1 Solve addition word problems with two-digit numbers
2-4 2 Solve subtraction word problems with two-digit numbers
3 Measurement and Data
3-1 Length
3-1 1 Compare the lengths of objects using non-standard units
3-1 2 Measure the lengths of objects using standard units (centimeters and meters)
3-2 Time
3-2 1 Tell time to the nearest hour and half-hour
3-2 2 Understand the concept of A M and P M
3-3 Data Collection
3-3 1 Collect and organize data in a simple bar graph
3-3 2 Interpret data from a simple bar graph
4 Geometry
4-1 Shapes
4-1 1 Identify and name basic 2D shapes (circle, square, triangle, rectangle)
4-1 2 Identify and name basic 3D shapes (cube, sphere, cone, cylinder)
4-2 Spatial Relationships
4-2 1 Understand and use positional words (above, below, beside, between, etc )
4-2 2 Understand and use directional words (left, right, forward, backward)
5 Patterns and Algebra
5-1 Patterns
5-1 1 Identify and extend simple patterns (AB, ABB, etc )
5-1 2 Create and describe patterns using shapes, colors, and numbers
5-2 Algebraic Thinking
5-2 1 Understand the concept of equality (e g , 3 + 2 = 5)
5-2 2 Use variables to represent unknown numbers in simple equations
2-2 Basic Subtraction

2-2 Basic Subtraction

Basic subtraction is a fundamental arithmetic operation that involves taking away one number from another to find the difference. This skill is essential for solving problems in everyday life, such as counting items left after some are taken away.

Key Concepts

1. Subtraction Symbol (-): The subtraction symbol is used to indicate that one number is being taken away from another. For example, in the expression 5 - 3, the subtraction symbol tells us to take away 3 from 5.

2. Difference: The result of a subtraction operation is called the difference. For example, in 5 - 3 = 2, the difference is 2.

3. Subtraction as the Opposite of Addition: Subtraction is the inverse operation of addition. If you add 3 to 2 to get 5, you can subtract 3 from 5 to get back to 2.

Detailed Explanation

When performing basic subtraction, follow these steps:

  1. Identify the numbers involved in the subtraction problem.
  2. Place the larger number first and the smaller number second, separated by the subtraction symbol (-).
  3. Subtract the smaller number from the larger number to find the difference.

Examples

Example 1: Subtract 3 from 7.

Example 2: Subtract 2 from 9.

Analogies to Help Understand

Think of subtraction as taking away marbles from a bag. If you have 8 marbles and you take away 3, you are left with 5 marbles. This is similar to the subtraction problem 8 - 3 = 5.

Another analogy is thinking of subtraction as climbing down stairs. If you are on the 10th step and you climb down 4 steps, you are now on the 6th step. This is similar to the subtraction problem 10 - 4 = 6.

By mastering basic subtraction, you can solve a variety of problems and understand the relationship between subtraction and addition.

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