Some children sold cards for a fund-raising event. Each small card was sold at $5 and each big card was sold at $8. The table below shows the number of cards sold by three of the children.

1. Calculate the amount collected by Janice.

Amount collected by Janice = $12 \times \char36{}5 + 7 \times \char36{}8 = \char36{}60 + \char36{}56 = \char36{}116$

2. Calculate the amount collected by Deepa.

Amount collected by Deepa = $7 \times \char36{}5 + 9 \times \char36{}8 = \char36{}35 + \char36{}72 = \char36{}107$

3. Calculate the amount collected by Zi Ying.

Amount collected by Zi Ying = $6 \times \char36{}5 + 10 \times \char36{}8 = \char36{}30 + \char36{}80 = \char36{}110$

4. Compare the amounts to find the maximum.

Comparing $\char36{}116$, $\char36{}107$, and $\char36{}110$, the largest amount is $\char36{}116$, collected by Janice.

1. Find the total number of cards Deepa sold and the amount she collected.

Total cards Deepa sold = $7 + 9 = 16$
Amount Deepa collected = $7 \times \char36{}5 + 9 \times \char36{}8 = \char36{}35 + \char36{}72 = \char36{}107$

2. Find Bradley's total cards and total amount collected.

Bradley's total cards = $16$
Bradley's amount collected = $\char36{}107 - \char36{}15 = \char36{}92$

3. Use the assumption method to find the number of small cards Bradley sold.

Assume all $16$ cards Bradley sold were big cards.
Total amount would be $16 \times \char36{}8 = \char36{}128$
Difference between assumed amount and actual amount = $\char36{}128 - \char36{}92 = \char36{}36$
Difference in price between a big card and a small card = $\char36{}8 - \char36{}5 = \char36{}3$
Number of small cards Bradley sold = $36 \div 3 = 12$