These videos deal with estimation skills, particularly for GCSE maths – although it’s good to have the ability to estimate and it’s useful for most calculations. The questions are aimed at around grade 3, and are usually a mix of both calculation, and word, problems:
1. Without using a calculator use your estimation skills, to work out the following answers
| a. | 6867 x 1.98 = |
| b. | 8091 x 0.92 = |
| c. | 39.5 x 1.7 x 5.003 = |
| d. | 44.44 ÷ 9.85 = |
| e. | 32204 ÷ 3134 = |
| f. | (59.35 x 9656) ÷ 9.92 = |
| g. | 7085 x 2.04 = |
| h. | 99 x 2.54 x 2.431 = |
| i. | 23 x 22 x 21 = |
| j. | 9156 ÷ 91 = |
| k. | 62000 ÷ 976 = |
| l. | π ÷ 3 = |
2. At the start of the week, a shop had approximately 26000 cartons of orange juice in stock. The shop sold 1487 on Monday, 2659 on Tuesday, 1678 on Wednesday, 1478 on Thursday, 2967 on Friday. Estimate the number of cartons remaining.
3. Mercy is painting her front room and needs to estimate the size, to buy enough paint to cover the walls. Two of the walls measure 3.17m x 2.89m, and the other two walls measure 3.56m x 2.89m. Estimate the area of the walls that Mercy needs to paint. If one tin of paint covers 9m2, how many tins of paint will Mercy need?
4. Explain how these calculations are wrong:
| a. | 13 x 0.9 = 11.6 |
| b. | 56 x 236 = 780 |
| c. | 0.8 ÷ 1.4 = 1.2 |
| d. | 5³ = -125 |
| e. | 25 x -25 = 625 |
| f. | 0.8 x 12 = 13.3 |
| g. | 38 = 4 |
| h. | 0.05² = 0.25 |
Here’s a link to the questions: Quick Test Estimation skills
and here’s the answer paper: Quick Test Estimation skills ANSWERS apologies for the fairly basic pdf – it might be better to watch the video 🙂
These types of questions appear in all the main GCSE exam boards – Edexcel, AQA, OCR and Educas.
Top Tips!
- It’s generally easier to round to 1 significant figure
- Is your answer reasonable? Use your estimation skills on all your calculations 🙂
Here’s a post that also might be of interest:
Please do leave a comment below if you are not sure. Alternately you can view my YouTube channel and leave a comment there – I’ll always try to respond as quickly as possible.
Watch this video on YouTube:
Estimation skills – GCSE maths how to estimate
How to estimate maths – GCSE maths estimation skills