Problem
The summer column has 2 circles, so 2 students were born in summer.
Counting a column's circles is direct picture-graph reading.
3.MD.B.3Draw A DiagramWinter is 2 times summer: 2 × 2 = 4 students born in winter.
'2 times' means double the summer count — a Grade 3 multiplication idea.
3.OA.A.3Identify SubproblemsThe number of students born in winter is 4.
Winter is 2 times the summer count, and 2 times a number means two equal groups, each as big as that number.
Two equal groups of 2, gathered together and counted, is exactly what multiplying 2 by 2 means.
Each of those equal groups holds 2, because the summer column shows 2 circles and every circle stands for one student.
Each circle is matched with exactly one student, so the number of circles is the number of students.
Total = spring + summer + autumn + winter = 6 + 2 + 5 + 4 = 17 students.
The whole survey is just the sum of every season's count.
3.MD.B.3Identify SubproblemsThis only needs Grade 3 'double it' multiplying and adding the columns — solve the knowable parts first!