Real-Life Problems
Maths: Year 3 & 4 National Curriculum, topic 1.2.6
Real-Life Problems
We can use our knowledge of number relationships, number facts and inverse operations to solve real-life problems. These are sometimes written down for us as word problems so that we can practise.
Word problems
- Word problems are a way of writing down a real life maths problem we need to solve.
- We need to work out what equation (number sentence) fits the word problem.
- Then we need to find the missing number.
Example
- Here is an example of a word problem:
- A school trip costs £306 altogether.
- The school will pay for £112 from the school fund.
- The pupils will pay the rest.
- How much will they need to charge the pupils altogether?
Missing number problem
- We can write this as a missing number problem with the equation:
- £112 + ? = £306
- We solve this missing number problem by using inverse operations:
- £306 - £112 = ?
Estimate
- We can use estimation to check our answer:
- £306 is near to £300
- £112 is near to £100
- £300 - £100 is related to the number fact 3 - 1.
- We can do this mentally:
- 3 - 1 = 2
- 300 - 100 = 200
Subtraction
- We can use a subtraction calculation method to work out £306 - £112:
- £306 - £112 = £194
- Our estimate was 200, so 194 seems reasonable.
Answer
- We have not finished yet because we need to answer the question.
- How much will they need to charge the pupils altogether?
- They will need to charge the pupils £194 altogether.