才念小学一年
I don’t fully understand the following sentence:
他才念小学一年级，只学过加法，还没学除法。

He + not until / only when + study + elementary school + first grade, only + studied + addition, still + not + study + division

My attempt at translating:
"Not until you will have been in elementary school’s first grade, will you know addition, not yet division."

It’s the 才 part that confuses me, because the sentence is not coherent in terms of continuity. To my ears the sentence would sound better without 才. (I’d use 才 when the last sentence would be positive, not negative (还没学)).

Can someone help me understand 才 in this sentence?

Question

才念小学一年
I don’t fully understand the following sentence:
他才念小学一年级，只学过加法，还没学除法。

He + not until / only when + study + elementary school + first grade,  only + studied + addition, still + not + study + division

My attempt at translating: 
"Not until you will have been in elementary school’s first grade, will you know addition, not yet division."

It’s the 才 part that confuses me, because the sentence is not coherent in terms of continuity. To my ears the sentence would sound better without 才. (I’d use 才 when the last sentence would be positive, not negative (还没学)).

Can someone help me understand 才 in this sentence?

Answer

"He only study in the first grade of primary school,just learnt addition, has not learned Division."
I think this translation may help you understand.
他才七岁=He is only seven years old.
The two “才” are of the same usage.
Hope it is helpful to you.

Answer

In this sentence  the"才"just emphasizes  the fact that  he is only in elementary school’s first grade

the“才”  often emphasizes a fact. it can be understood  as "only,just,literly and so on." 
  e.g     他才两岁（only）
             你才学会游泳？！（literly）                  
 "才"  is also a  conjunction 。  
 e.g   昨晚我熬夜到凌晨一点才睡  （I didn't go to bed until 1 a.m）

Answer

It's vear esay to understand.The meaning of 才 in this sentence means    only    .I would translate it in this way:He is only a student who is in elementary school’s first grade,therefore,he only knows the addition.And he hasn't learned the division.yet.It's all.