Mathematics 12. Add and subtract within 1000 using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method.
a. Explain that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.
Unpacked Content
Evidence Of Student Attainment:
Students:
add and subtract within 1000.
explain their reasoning using concrete models or drawings, or using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
relate the strategy used to a written method (symbolic and numeric recording of the steps used). Teacher Vocabulary:
Knowledge:
Students know:
how to count to 1,000.
how to identify hundreds, tens, and ones.
how to compose numbers.
how to decompose two digit numbers.
how to record strategies for solving addition and subtraction problems.
Skills:
Students are able to:
add and subtract within 1000.
model addition problems using visual models.
record strategies for solving addition problems.
communicate the relationship between models and symbolic (numeric) representations. Understanding:
Students understand that:
relationships between models of addition/subtraction problems and written strategies of those models can be used to justify solutions. Diverse Learning Needs:
Essential Skills:
Learning Objectives: M.2.12.1: Define regrouping, total, sum, difference and solve.
M.2.12.2: Add and subtract two two-digit numbers with and without regrouping.
M.2.12.3: Determine the value of the number in the ones, tens, hundreds and thousands place using concrete models or drawings and strategies based on place value.
M.2.12.4: Match the number in the ones, tens, hundreds and thousands position to a pictorial representation or manipulative of the value.
M.2.12.5: Model written method for recording horizontal and vertical addition and subtraction problems.
M.2.12.6: Represent two- and three-digit numbers with multiple models.
M.2.12.7: Recall single-digit addition and subtraction facts.
M.2.12.8: Add and subtract within 20, e.g., by using objects or drawings to represent the problem.
Prior Knowledge Skills:
Notice same/different and some/all.
Recognize numerals from 1-50.
Add one to a set of objects (up to 10 objects).
Given small groups of objects, create larger groups by combining the small groups.
Understand ten and 1 (ten 1's =10).
Put together two small groups of objects to create a larger group.
Subtract one from a set of objects (up to 10 objects).
Given a group of objects (20 or less), divide the group into smaller groups in various ways.
Take away objects from a large group to create two smaller groups.
Understand number words.
Establish one-to-one correspondence between numbers and objects when given a picture a drawing or objects.
Rote count to 10.
Understand amount words, such as more, less, and another.
Begin to understand that parts of an object can make a whole.
Alabama Alternate Achievement Standards
AAS Standard:
