Choose exam board for KS4 Computer Science (GCSE)
Choose exam board for KS4 English
Choose exam board for KS4 French
Choose exam board for KS4 Geography
Choose exam board for KS4 German
Choose exam board for KS4 History
Choose tier for KS4 Maths
Choose exam board for KS4 Music
Choose exam board for KS4 Physical education (GCSE)
Choose exam board for KS4 Religious education (GCSE)
Choose exam board for KS4 Spanish

      Rounding integers to one significant figure

      Lesson details

      Learning outcome

      I can round integers to one significant figure.

      Key learning points

      1. It is possible to use rounding and place value to know the size of a number without knowing the actual number.
      2. The first non-zero digit of a number is the first significant figure.
      3. You can identify the place value of the first significant figure.
      4. A number can be located on a number line and numbers to 1 significant figure either side of it represented.
      5. Any integer can be rounded to one significant figure and a number line can help with this.

      Keywords

      • Significant figure - Significant figures are the digits in a number that contribute to the accuracy of the number. The first significant figure is the first non-zero digit.

      • Round - To change a number into another number that is approximately the same value but is easier to work with. E.g. round 561 to the nearest 10 is 560.

      Common misconception

      Assuming all zero digits are not significant.

      Within the lesson there are many examples where some zeros are significant. Relate significance back to the communication of accuracy and that some digits are significant as they preserve the place value of other digits.

      Teacher tip

      Pupils could come up with their own coded words or messages using the grid in the 3rd learning cycle. This will give pupils the opportunity to embed their understanding of significant figures. They can then swap and decode each others words or messages.

      Licence

      This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0
      except where otherwise stated. See Oak's terms & conditions
      (Collection 2).

      Lesson video

      Loading...

      Prior knowledge starter quiz

      6 Questions

      Q1.
      A degree of shows how precise a number or measurement is. Examples are: to the nearest cm, to the nearest 10, to 1 s.f. and 2 d.p.

      Correct Answer: accuracy

      Q2.
      Round 15.076 to two decimal places.

      Correct Answer: 15.08

      Q3.
      Round 0.0504 to one decimal place.

      Correct Answer: 0.1

      Q4.
      Round 20.961 to 1 decimal place.

      Correct Answer: 21.0

      Q5.
      Calculate the cost of carpeting this area.

      An image in a quiz
      Correct Answer: £76.73, 76.73

      Q6.
      3 friends go out for lunch and spend £31. They pay the same amount each. What is the smallest amount they each pay to cover the cost of the bill?

      Correct Answer: £10.34, 10.34

      6 Questions

      Q1.
      The first significant figure is the first non- digit in a number.

      Correct Answer: zero, 0

      Q2.
      Select all the numbers which have 4 as the first significant figure.

      Correct answer: 4698
      54 875
      Correct answer: 403 146
      644 145
      Correct answer: 4 002 231

      Q3.
      In the number 654 023, in which column is the first significant figure?

      tens
      hundreds
      thousands
      ten thousands
      Correct answer: hundred thousands

      Q4.
      Match each number to its value when it is rounded to one significant figure.

      Correct Answer:4 564 231,five million

      five million

      Correct Answer:52.96,fifty

      fifty

      Correct Answer:48 264,fifty thousand

      fifty thousand

      Correct Answer:5365.12,five thousand

      five thousand

      Correct Answer:496 568,five hundred thousand

      five hundred thousand

      Q5.
      Round 654 023 to one significant figure.

      Correct Answer: 700 000

      Q6.
      What value could the missing digit be in 3$$\square$$89 = 4000 (to 1 s.f.)?

      3
      4
      Correct answer: 5
      Correct answer: 6
      Correct answer: 7

      To help you plan your 8 maths lesson on: Rounding integers to one significant figure, download all teaching resources for free and adapt to suit your pupils' needs...