Problem
Sum the heights of all four bars to get the total number of grid squares used.
All the squares together stand for all the students.
3.MD.B.3Identify SubproblemsThose 23 squares represent all 46 students, so one square represents 46 divided by 23.
Sharing 46 students evenly across 23 squares gives 2 per square.
3.OA.A.3Analyze The UnitsDividing the 46 students by the 23 grid squares gives 2, the number of students one grid square stands for.
The 23 grid squares together stand for all 46 students, because each bar's squares stand for that bar's students and the four bars together account for every student with none left out or counted twice.
Since those 23 equal squares together make 46 students, the number of students in one square is 46 split into 23 equal parts, which is 46 divided by 23.
23 squares that each hold the same number of students are 23 equal groups, so 23 groups totaling 46 students is a multiplication situation.
Division reverses that multiplication, so splitting the 46 students back into 23 equal groups recovers how many students are in one square.
Lincoln's bar is 8 squares tall, and each square is worth 2 students, so multiply.
8 squares each worth 2 students make 16 students.
3.OA.A.3Analyze The UnitsThis only needs Grade 3 division: share the total over all the squares to learn what one square is worth!