1.3 Adding and Subtracting Within 20
- Students add and subtract within 20. Students apply the properties of operations and the relationship between addition and subtraction.
Section A Goals
- Build toward fluency with adding and subtracting within 10.
Section B Goals
- Add and subtract one-digit numbers from teen numbers without composing or decomposing a ten.
- Find the value that makes an addition or subtraction equation true, involving 10.
- Understand 10 ones as a ten and the numbers 11 to 19 as a ten and some ones.
Section C Goals
- Add within 20, including three addends.
Section D Goals
- Subtract within 20.
- categoryA label that tells how objects in a group are alike.
- dataInformation about the things or people in a group.
Example: If you have a box of colored pencils, then the lengths and colors of each of the pencils are data about the pencils in the box.
- differenceThe result when one number is subtracted from another.
- sumThe total when two or more numbers are added.
- surveyA way to collect data using a group of people answering the same question.
- teen number
A number with 1 ten and between 1 and 9 ones.
Fifteen is 1 ten and 5 ones.