Recognize and create patterns; use rules to describe patterns.

Benchmarks1. Create simple patterns using objects, pictures, numbers and rules. Identify possible rules to complete or extend patterns. Patterns may be repeating, growing or shrinking. Calculators can be used to create and explore patterns.

ExamplesDescribe rules that can be used to extend the pattern 2, 4, 6, 8, , ,  and complete the pattern 33, 43, , 63, , 83 or 20, , , 17.
Use number sentences involving addition and subtraction basic facts to represent and solve real-world and mathematical problems; create real-world situations corresponding to number sentences.
Benchmarks

Examples
1. Represent real-world situations involving addition and subtraction basic facts, using objects and number sentences.

One way to represent the number of toys that a child has left after giving away 4 of 6 toys is to begin with a stack of 6 connecting cubes and then break off 4 cubes
2. Determine if equations involving addition and subtraction are true.

Determine if the following number sentences are true or false
7 = 7
7 = 8 – 1
5 + 2 = 2 + 5
4 + 1 = 5 + 2.

3. Use number sense and models of addition and subtraction, such as objects and number lines, to identify the missing number in an equation such as:

2 + 4 = 
3 +  = 7
5 =  – 3.