# Kansas - Grade 1 - Math - Operations and Algebraic Thinking - Addition and Subtraction Word Problems - 1.OA.1

### Description

Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions.

• State - Kansas
• Standard ID - 1.OA.1
• Subjects - Math Common Core

### Keywords

• Math
• Operations and Algebraic Thinking

## More Kansas Topics

1.NBT.2 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 grouping 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). (d) Show flexibility in composing and decomposing tens and ones.

1.OA.4 Understand subtraction as an unknown-addend problem.

1.OA.5 Relate counting to addition and subtraction.

1.OA.6 Add and subtract within 20, demonstrating fluency (efficiently, accurately, and flexibly) for addition and subtraction within 10. Use mental strategies such as counting on; making ten; decomposing a number leading to a ten; using the relationship between addition and subtraction; and creating equivalent but easier or known sums.

1.OA.7 Understand the meaning of the equal sign (the value is the same on both sides of the equal sign), and determine if equations involving addition and subtraction are true or false.

1.OA.8 Using related equations, determine the unknown whole number in an addition or subtraction equation.

Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

Compose two-dimensional shapes (rectangles, squares, trapezoids, triangles, half-circles, and quarter-circles) or three-dimensional shapes (cubes, right rectangular prisms, right circular cones, and right circular cylinders) to create a composite shape, and compose new shapes from the composite shape. Students do not need to learn formal names such as “right rectangular prism.”