Task statements for students to write on. Unit: 1.3 Adding and Subtracting Within 20 (Grade 1). 1.3 Adding and Subtracting Within 20 Unit Goals 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