△ Calculate the total cost of buying one pen and one schoolbag.
○ Calculate the price of the schoolbag.
☼ The schoolbag costs \( 4 \times 15 = 60 \) yuan. Its price is 4 times the price of a pen, which is 15 yuan.
○ Calculate the total cost.
☼ The total cost is \( 15 + 60 = 75 \) yuan. Adding the price of the pen and the schoolbag gives the total.
✧ The total cost is 75 yuan.
△ Calculate the total number of books on the shelf.
○ Calculate the number of science books.
☼ There are \( 36 - 12 = 24 \) science books. Science books are 12 fewer than story books, and there are 36 story books.
○ Calculate the total number of books.
☼ The total number of books is \( 36 + 24 = 60 \). Adding the number of story books and science books gives the total.
✧ The total number of books is 60.
△ Calculate the change Xiao Ming should receive after buying a toy.
○ Subtract the toy's price from the amount paid.
☼ Xiao Ming should receive \( 100 - 85 = 15 \) yuan. He paid 100 yuan for a toy costing 85 yuan.
✧ Xiao Ming should receive 15 yuan.
△ Calculate how many more pear trees there are than peach trees.
○ Calculate the number of pear trees.
☼ There are \( 24 \times 3 = 72 \) pear trees. The number of pear trees is 3 times the number of peach trees, which is 24.
○ Calculate the difference in the number of trees.
☼ The difference is \( 72 - 24 = 48 \). Subtracting the number of peach trees from the number of pear trees gives the difference.
✧ There are 48 more pear trees than peach trees.
△ Calculate the fraction of the cake remaining after Xiao Hong eats her portion.
○ Subtract the fraction Xiao Hong ate from the whole cake.
☼ The remaining fraction is \( 1 - \frac{3}{8} = \frac{5}{8} \). Xiao Hong ate \( \frac{3}{8} \) of the cake, leaving \( \frac{5}{8} \).
✧ The remaining fraction of the cake is \( \frac{5}{8} \).
△ Calculate the factory's new daily water usage.
○ Multiply the original water usage by the fraction representing the reduction.
☼ The new daily water usage is \( 12 \times \frac{2}{3} = 8 \) tons. The factory now uses \( \frac{2}{3} \) of its original daily water usage, which was 12 tons.
✧ The factory's new daily water usage is 8 tons.
☺1. 75 元
2. 60 本
3. 15 元
4. 48 棵
5. $\frac{5}{8}$
6. 8 吨
Answered
