Mixed addition and subtraction (Three digits)：練習問題

Solve the following:
\( 850 - 450 + 100 = ? \)

A school held a book fair over three days. On the first day, students bought 358 books. On the second day, they bought 125 fewer books than the first day. On the third day, a delivery of 200 new books arrived to restock. How many books were bought on the second day?

Calculate the value of \(912 - (345 + 288)\).

There were 645 passengers on a train. 128 passengers got off at the first stop, and 204 new passengers got on at the second stop. How many passengers are on the train now?

A toy shop had \(420\) building blocks. They sold \(150\) blocks in the morning and bought \(230\) new blocks in the afternoon. How many building blocks does the shop have now?

A flower shop had 520 roses. They sold 145 roses in the morning and received a new delivery of 280 roses in the afternoon. How many roses does the flower shop have now?

Fill in the blank with the correct three-digit number:
\(235 + \text{___} - 150 = 385\)

Calculate the value of \(X\) in the following problem:
A car dealership had 450 cars. They sold some cars \((X)\), received a shipment of 125 cars, and then sold 88 more cars. If they now have 362 cars, what is \(X\)?

A farmer harvested 345 oranges on Monday and 258 oranges on Tuesday. On Wednesday, he sold 412 oranges at the market.
a) How many oranges did the farmer harvest in total on Monday and Tuesday?
b) How many oranges does the farmer have left after the sales on Wednesday?

Find the value of the expression: \( 900 - (250 + 380) \).
a) Solve the addition inside the brackets first.
b) Subtract your result from 900 to find the final value.
c) Does the answer change if we calculate \( 900 - 250 + 380 \) instead? Explain why.