Question 14

We will count the girl symbols in each class and use the key to find the number of girls.

Step 1 — Understand the pictograph key

Look at the top right of the diagram. One full girl symbol stands for 4 girls. A half girl symbol stands for half of 4 girls. Half of 4 girls is 2 girls.

Step 2 — Calculate girls in each class

Let us count the girls for each class.

Class 1 has 7 full symbols. Number of girls in Class 1: $7 \times 4$ $= 28 \text{ girls}$

Class 2 has 4 full symbols and 1 half symbol. Number of girls in Class 2: $4 \times 4 + 0.5 \times 4$ $= 16 + 2$ $= 18 \text{ girls}$

Class 3 has 5 full symbols. Number of girls in Class 3: $5 \times 4$ $= 20 \text{ girls}$

Class 4 has 3 full symbols and 1 half symbol. Number of girls in Class 4: $3 \times 4 + 0.5 \times 4$ $= 12 + 2$ $= 14 \text{ girls}$

Class 5 has 2 full symbols and 1 half symbol. Number of girls in Class 5: $2 \times 4 + 0.5 \times 4$ $= 8 + 2$ $= 10 \text{ girls}$

Class 6 has 4 full symbols. Number of girls in Class 6: $4 \times 4$ $= 16 \text{ girls}$

Class 7 has 3 full symbols. Number of girls in Class 7: $3 \times 4$ $= 12 \text{ girls}$

Class 8 has 1 full symbol and 1 half symbol. Number of girls in Class 8: $1 \times 4 + 0.5 \times 4$ $= 4 + 2$ $= 6 \text{ girls}$

Step 3 — Answer part (a): Class with least girls

We compare the number of girls in all classes. The numbers are 28, 18, 20, 14, 10, 16, 12, 6. The smallest number is 6. This number of girls is in Class 8.

$\boxed{\text{Class 8}}$

Step 4 — Answer part (b): Difference between Class 5 and 6

Class 6 has 16 girls. Class 5 has 10 girls. We subtract the smaller number from the larger number. Difference in girls: $16 - 10$

$\boxed{6 \text{ girls}}$

Step 5 — Answer part (c): Graph change for Class 2

Class 2 currently has 18 girls. Two more girls are admitted. Total girls in Class 2 will be: $18 + 2$ $= 20 \text{ girls}$ Each symbol stands for 4 girls. Number of symbols needed for 20 girls: $20 \div 4$ $= 5 \text{ symbols}$ The graph would show 5 full symbols for Class 2.

$\boxed{\text{Class 2 would show 5 full symbols}}$

Step 6 — Answer part (d): Girls in Class 7

Class 7 has 3 full symbols. Each symbol stands for 4 girls. Total girls in Class 7: $3 \times 4$

$\boxed{12 \text{ girls}}$

Answer

(a) Class 8 has the least number of girl students. (b) The difference is 6 girls. (c) Class 2 would show 5 full symbols. (d) There are 12 girls in Class 7.