MA19.1.1c
Put together/take apart with addend unknown to solve word problems within 20.
Put together/take apart with addend unknown to solve word problems within 20.
Put together/take apart with addend unknown to solve word problems within 20.
Compare quantities, with difference unknown, bigger unknown, and smaller unknown while solving word problems within 20.
Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20 by using concrete objects, drawings, or equations with a symbol for the unknown number to represent the problem.
Apply properties of operations as strategies to add and subtract.
Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known (commutative property of addition).
To add 2 + 6 + 4, the second and third numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12 (associative property of addition).
When adding 0 to a number, the result is the same number (identity property of zero for addition).
Explain subtraction as an unknown-addend problem.
Example: subtracting 10 - 8 by finding the number that makes 10 when added to 8
Relate counting to addition and subtraction.
Example: counting on 2 to add 2
Add and subtract within 20.
Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by counting on.
Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by making ten.
Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by decomposing a number leading to a ten.
Example: 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9
Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by using the relationship between addition and subtraction.
Example: Knowing that 8 + 4 = 12, one knows 12 - 8 = 4.
Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by creating equivalent but easier or known sums.
Example: adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13
Explain that the equal sign means the same as.“ Determine whether equations involving addition and subtraction are true or false.“
Example: determining which of the following equations are true and which are false: 6 = 6, 7 = 8 - 1, 5 + 2 = 2 + 5, 4 + 1 = 5 + 2
Solve for the unknown whole number in various positions in an addition or subtraction equation, relating three whole numbers that would make it true.
Example: determining the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, and 6 + 6 = ?
Reproduce, extend, and create patterns and sequences of numbers using a variety of materials.
Extend the number sequence from 0 to 120.
Count forward and backward by ones, starting at any number less than 120.
Read numerals from 0 to 120.
Write numerals from 0 to 120.
Represent a number of objects from 0 to 120 with a written numeral.
Explain that the two digits of a two-digit number represent amounts of tens and ones.
Identify a bundle of ten ones as a ten.““
Identify the numbers from 11 to 19 as composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.
Identify the numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 as one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).
Compare pairs of two-digit numbers based on the values of the tens and ones digits, recording the results of comparisons with the symbols >, =, and < and orally with the words “is greater than,” “is equal to,” and “is less than.”
Students know:
Students are able to:
Students understand that:
Add within 100, using concrete models or drawings and strategies based on place value.
Add a two-digit number and a one-digit number.
Add a two-digit number and a multiple of 10.
Demonstrate that in adding two-digit numbers, tens are added to tens, ones are added to ones, and sometimes it is necessary to compose a ten.
Relate the strategy for adding a two-digit number and a one-digit number to a written method and explain the reasoning used.
Given a two-digit number, mentally find 10 more or 10 less than the number without having to count, and explain the reasoning used.
Subtract multiples of 10 from multiples of 10 in the range 10-90 (positive or zero differences), 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 and explain the reasoning used.
Organize, represent, and interpret data with up to three categories.
Ask and answer questions about the total number of data points in organized data.
Summarize data on Venn diagrams, pictographs, and yes-no“ charts using real objects symbolic representations or pictorial representations.“