# South Carolina - Grade 1 - Math - Algebraic Thinking and Operations - Adding and Subtracting within 20 - 1.ATO.4, 1.ATO.5, 1.ATO.6

### Description

1.ATO.4 Understand subtraction as an unknown addend problem. 1.ATO.5 Recognize how counting relates to addition and subtraction. 1.ATO.6 Demonstrate: a. addition and subtraction through 20; b. fluency with addition and related subtraction facts through 10.

• State - South Carolina
• Standard ID - 1.ATO.4, 1.ATO.5, 1.ATO.6
• Subjects - Math Common Core

### Keywords

• Math
• Algebraic Thinking and Operations

## More South Carolina Topics

1.ATO.7 Understand the meaning of the equal sign as a relationship between two quantities (sameness) and determine if equations involving addition and subtraction are true.

1.ATO.8 Determine the missing number in addition and subtraction equations within 20.

Partition two-dimensional shapes (i.e., square, rectangle, circle) into two or four equal parts.

Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases: A. 10 can be thought of as a bundle of ten ones — called a “ten.” B. The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones. C. The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).

Use nonstandard physical models to show the length of an object as the number of same size units of length with no gaps or overlaps.

Apply Commutative and Associative Properties of Addition to find the sum (through 20) of two or three addends.