A lesson on significant figures M A T H S MIXED STARTER Write the first five prime numbers. Round 8.564 to 2d.p. Write the HCF of 10 and 15 John has £4 to spend at the newsagent. He spends 30% of his money on sweets and 60% of the remainder on comics. How much does John have left? A lesson on significant figures Write the LCM of 3 and 4 Find the product of prime factors for 18. LO: To round values to a given significant figure

Rounding to significant figures A lesson on significant figures Thursday, 03 May 2018 Rounding to significant figures Core: will be able to write numbers using words and understand the value of each digit Challenge: will be able to round to significant figures Aspire: to be able to describe the difference between rounding and rounding to significant figures Vivo Star: Understand the importance of rounding to significant figures Key words – tenths, hundredths, figures, value A lesson on significant figures LO: To round values to a given significant figure

A Significant figures A lesson on significant figures Round 291.57 to M A T H S ACQUIRE FLUENCY Rounding decimals Order the following decimals in ascending order (smallest first) Round 291.57 to To the nearest 100? to the nearest 10? to the nearest whole number? to one decimal place? (a) 3.3, 0.5, 1.9, 1.7, 2.4 (b) 0.15, 0.35, 0.24, 0.79, 0.55 (c) 5.7, 5.67, 5.689,5.698, 5.69 A lesson on significant figures Adding and subtracting decimals (a) 3.4 + 2.1 8.0 – 5.6 (b) 7.1 + 5.4 8.5 – 7.1 (c) 4.3 + 1.6 9.5 – 1.7 LO: To round values to a given significant figure

A lesson on significant figures M A T H S TALK ABOUT IT Round the following number to 2 significant figures 492177 Working from the left the 4 and 9 are the first two most significant numbers so we round after these, therefore = 490000 A lesson on significant figures LO: To round values to a given significant figure

A lesson on significant figures M A T H S TALK ABOUT IT You are going to be shown a number of celebrities and how many people follow them on Twitter You then need to round these to the number of significant figures indicated The next slide shows you how I would like you to lay out your answers in your book A lesson on significant figures LO: To round values to a given significant figure

A lesson on significant figures M A T H S TALK ABOUT IT A lesson on significant figures LO: To round values to a given significant figure

A lesson on significant figures M A T H S HAVE A GO Lady Gaga 32,243,526 followers 2 sig figs 4 sig figs 5 sig figs A lesson on significant figures LO: To round values to a given significant figure

A lesson on significant figures M A T H S HAVE A GO Cristiano Ronaldo 14,960,666 followers 1 sig figs 2 sig figs 6 sig figs A lesson on significant figures LO: To round values to a given significant figure

A lesson on significant figures M A T H S HAVE A GO Adele 11,001,473 followers 1 sig figs 3 sig figs 6 sig figs A lesson on significant figures LO: To round values to a given significant figure

A lesson on significant figures M A T H S HAVE A GO Charlie Sheen 8,604,801 followers 1 sig figs 3 sig figs 6 sig figs A lesson on significant figures LO: To round values to a given significant figure

A lesson on significant figures M A T H S HAVE A GO Dalia Lama 5,763,274 followers 1 sig figs 3 sig figs 6 sig figs A lesson on significant figures LO: To round values to a given significant figure

A lesson on significant figures M A T H S HAVE A GO David Beckham 508,995 followers 1 sig figs 3 sig figs 5 sig figs A lesson on significant figures LO: To round values to a given significant figure

S Set Review the lesson SUM IT UP A T H S SUM IT UP 3 The larger of two square numbers that sum to 97 The sum of the first six prime numbers 6 Round the following to 2 d.p. 134.182 2157.357 (5 marks) 1 (4 marks) The highest common factor of 80 and 64 4 (2 marks) Round the following to 2 s.f. 13.4182 215.7357 (4 marks) 2 5 The lowest common multiple of 9 and 15 (2 marks) (3 marks)

A lesson on significant figures M A T H S SUM IT UP Main When you are rounding to decimal places you start counting after the decimal point, but with significant figures you start counting at the first non zero number 1000 1500 1460 200 160 157 40 37 37.1 6 6.1 6.09 0.006 0.0064 0.00640 4.7 0.058 0.19 540 A lesson on significant figures LO: To round values to a given significant figure