Decimals (Mixed operations of addition and subtraction)：練習問題

Calculate the following expression:
\(5.4 + 2.8 - 3.1\)

A wooden board is \( 9.2 \text{ m} \) long. A carpenter cuts off a piece of \( 3.65 \text{ m} \) and another piece of \( 2.8 \text{ m} \). What is the length of the remaining board?

There were \(20.5\) L of water in a tank. \(8.75\) L was poured out in the morning, and \(12.4\) L was added in the afternoon. How much water is in the tank now?

Find the value of \(12.75 - 4.2 + 1.15\).

Solve the following mixed operation:
\(15 - 6.45 + 2.8\)

Find the value of \( 45.3 - 12.85 + 7.4 \).

A student tracks the volume of liquid in a container during a science experiment. The container initially has \( 8.4 \text{ L} \) of liquid. Over three steps:

- Step 1: \( 3.75 \text{ L} \) is poured out.
- Step 2: \( 12.65 \text{ L} \) is added.
- Step 3: \( 6.9 \text{ L} \) is poured out.

a) Find the volume of liquid in the container after Step 2.

b) Find the final volume of liquid in the container after Step 3.

A fruit vendor had \( 60 \text{ kg} \) of oranges. On Monday, he sold \( 24.35 \text{ kg} \). On Tuesday, he sold \( 18.9 \text{ kg} \). On Wednesday, a new shipment of \( 35.5 \text{ kg} \) was added to the stock.

a) What was the total weight of oranges sold on Monday and Tuesday combined?

b) How many kilograms of oranges were in stock at the end of Tuesday?

c) What was the final weight of oranges in stock after the shipment arrived on Wednesday?