# Module 4

### Place Value, Comparison, Addition and Subtraction to 40

## Standards

1.OA.A.1: 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, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

- I can use a symbol (e.g. ?, X) to represent an unknown number in a problem.
- I can determine the operation to solve world problems with unknowns.
- I can solve world problems by adding 3 numbers in different ways.

1.NBT.1 Count to 120, starting at any number less than 120. In this range, read and write numerals and represent a number of objects with a written numeral.

- I can write numerals up to 120.
- I can write a numeral to represent a number of objects.
- I can count to 120 starting with a given number.
- I can read the numerals up to 120

1.NBT.2 Understand that the two digits of a two-digit number represent amounts of tens and ones

- I can explain what each digit of a two-digit number represents.
- I can identify a bundle of 10 ones as a βtenβ.
- I can represent numbers 11 to 19 as a 10 and ones.
- I can represent numbers 20 to 90 as tens and zero ones.

1.NBT.3 Compare two two-digit numbers based on meaning of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <.

- I can identify the value of each digit in a two-digit number.
- I can explain what each symbol means (>, <, =).
- I can compare two 2 digit numbers.
- I can use >, <, = symbols to compare two 2 digit numbers.

1.NBT.4 Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, 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. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.

- I can show that in adding 2 digit numbers, you add ones to ones and tens to tens.
- I can recognize when to regroup to compose (make) a ten.
- I can add a 2 digit number and a 1 digit number within 100.
- I can add a 2 digit number and 1 digit number with regrouping within 100.
- I can add a 2 digit number and a multiple of 10 within 100.
- I can relate the strategy to an equation.
- I can explain why I used a chosen strategy to solve a written equation.

1.NBT.5 Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

- I can mentally add 10 to a given 2 digit number.
- I can mentally subtract 10 from a given 2 digit number.
- I can explain how to find 10 more than a given 2 digit number.
- I can explain how to find 10 less than a given 2 digit number.

1.NBT.6 Subtract multiples of 10 in the range 10β90 from multiples of 10 in the range 10β90 (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.

- I can subtract multiples of 10 up to 90.
- I can choose a strategy to solve subtraction problems with multiples of 10,
- I can relate the strategy to an equation.
- I can explain why I used the chosen strategy to solve a written equation.