Add, then subtract
A school sold 1,245 tickets on Friday and 1,130 on Saturday, then refunded 85. The final total was 2,290.
Read the events in order.
Year 4
Solve addition and subtraction two-step problems in contexts, deciding which operations and methods to use and why
Read two-step problems carefully, decide which operations are needed, and choose a method that fits the numbers.
Lesson overview
Number - addition and subtraction
Two-step problems need us to stop and think about what happens first and what happens next. Sometimes we combine and then subtract. Sometimes we subtract first and then compare or add.
Subtract to find what is left
A library had 3,500 books. 428 were taken out and 175 were returned. Now there are 3,247 books.
The number changes more than once.
Use the context
Words such as altogether, left, more and difference help choose the operation.
often add
often subtract
compare carefully
often subtract
The wording gives clues.
Worked example
A shop sold 1,250 pencils on Monday and 980 on Tuesday. Then 300 more arrived. How many pencils are there altogether now?
- First combine the pencils sold on Monday and Tuesday: 1,250 + 980 = 2,230.
- Then add the 300 more that arrived.
- 2,230 + 300 = 2,530.
- So there are 2,530 pencils altogether now.
Round 1: Learn it
Read each problem slowly and decide what happens first and second.
Finish this round to unlock Round 2: Show you know it.
Question 1
A farm collected 1,230 eggs on Monday and 980 on Tuesday. How many eggs were collected altogether?
Question 2
A hall had 3,400 chairs. 275 were removed. Then 125 were added back. How many chairs are there now?
Question 3
A library had 4,000 books. 350 were borrowed and then 120 were returned. How many books are there now?
Question 4
Which operation is most likely for the words 'how many more'?
how many more
altogether
Question 5
A school raised 1,450 pounds in autumn and 1,275 pounds in spring, then spent 500 pounds. Which answer is correct?
Common mistakes
Watch for these as you work through the lesson.
- Choosing the wrong operation from the wording.
- Missing the second step in the problem.
- Solving the calculation correctly but answering the wrong question.
Related topics
These ideas connect closely to this lesson.
- Add and subtract numbers with up to 4 digits using the formal written methods of columnar addition and subtraction where appropriate.
- Estimate and use inverse operations to check answers to a calculation.