Question 1
A third-grade teacher uses an open number line to model 48 + 25 by jumping 20, then 5. This representation mainly helps students
- A.learn the vocabulary word "sum."
- B.understand addition as composing tens and ones.
- C.practice writing numerals neatly.
- D.memorize the addition facts to 20 so that they can recall them without counting.
Show the answer and explanation
Answer: B: understand addition as composing tens and ones.
An open number line shows how numbers can be broken into tens and ones and added in parts, building understanding of place value and mental strategies.
