DLI 1st grade guide

Operations and Algebraic Thinking

Core Guide

Grade 1

Understand and apply properties of operations and the relationship between addition and subtraction (Standards 3–4) Standard 1.OA.3 Apply properties of operations as strategies to add and subtract. For example: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 =12. (Associative property of addition.) First grade students need not use formal terms for these properties. Concepts and Skills to Master • Understand the commutative property of addition (8 + 3 = 11 and 3 + 8 = 11) • Understand that the commutative property does not work with subtraction (8 - 3 = 5, but 3 - 8 does not equal 5) • Understand the associative property of addition (2 + 6 + 4 = 2 + 10 = 12)

• Understand the additive identity property of zero (8 + 0 = 8) • Understand the identity property of subtraction (8 - 0 = 8) • Apply properties listed above as strategies to add and subtract

Teacher Note: Emphasis should be placed on understanding of the properties and why each property applies to a particular operation rather than memorizing names and definitions.

Related Standards: Current Grade Level

Related Standards: Future Grade Levels

1.OA.4 Understand subtraction as an unknown addend problem 1.OA.6 Add and subtract within 20 1.NBT.4 Add within 100 1.NBT.6 Subtract multiples of 10

2.NBT.5, 2.NBT.7 Add and subtract within 100 and within 1,000 2.NBT.6 Add up to 4 two-digit numbers 2.NBT.8 Mentally add and subtract 10 or 100 from a given number 2.NBT.9 Explain why addition and subtraction strategies work 3.OA.5 Apply properties of operations to multiply and divide 3.NBT.2 Fluently add and subtract within 1,000

Critical Background Knowledge from Previous Grade Levels • Solve addition and subtraction word problems within 10 (K.OA.2) Academic Vocabulary add, subtract, equation, total, difference Suggested Strategies • Use objects or drawings to represent properties listed above • Number bonds, ten-frames, related facts, abacuses • Use context to interpret the properties (5 green apples and 3 red apples amounts to the same number of apples as 3 green apples and 5 red apples)

1.OA.3

ADA Compliant 1/13/2020