  # Tennessee - Grade 1 - Math - Operations and Algebraic Thinking - Adding and Subtracting within 20 - 1.OA.4, 5, 6

### Description

(4) Understand subtraction as an unknown-addend problem. For example, to solve 10 – 8 = ___, a student can use 8 + ___ = 10. (5) Add and subtract within 20 using strategies such as counting on, counting back, making 10, using fact families and related known facts, and composing/ decomposing numbers with an emphasis on making ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9 or adding 6 + 7 by creating the known equivalent 6 + 4 + 3 = 10 + 3 = 13). (6) Fluently add and subtract within 20 using mental strategies. By the end of 1st grade, know from memory all sums up to 10.

• State - Tennessee
• Standard ID - 1.OA.4, 5, 6
• Subjects - Math Common Core

### Keywords

• Math
• Operations and Algebraic Thinking

## More Tennessee Topics Add three whole numbers whose sum is within 20 to solve contextual problems using objects, drawings, and equations with a symbol for the unknown number to represent the problem. Count to 120, starting at any number. Read and write numerals to 120 and represent a number of objects with a written numeral. Count backward from 20. Add a two-digit number to a one-digit number and a two-digit number to a multiple of ten (within 100). Use concrete models, drawings, strategies based on place value, properties of operations, and/or the relationship between addition and subtraction to explain the reasoning used. Subtract multiples of 10 from multiples of 10 in the range 10-90 using concrete models, drawings, strategies based on place value, properties of operations, and/or the relationship between addition and subtraction. Order three objects by length; compare the lengths of two objects indirectly by using a third object.

## Here is the skill that Tennessee requires you to master

• State Standards Tennessee State Standards
• Subject Math
• Topic Name Adding and Subtracting within 20
• Standard ID 1.OA.4, 5, 6
• Description
(4) Understand subtraction as an unknown-addend problem. For example, to solve 10 – 8 = ___, a student can use 8 + ___ = 10. (5) Add and subtract within 20 using strategies such as counting on, counting back, making 10, using fact families and related known facts, and composing/ decomposing numbers with an emphasis on making ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9 or adding 6 + 7 by creating the known equivalent 6 + 4 + 3 = 10 + 3 = 13). (6) Fluently add and subtract within 20 using mental strategies. By the end of 1st grade, know from memory all sums up to 10.  