Integers

1. Integers Significant Figures Estimating Order of Operation www.mathsrevision.com Revision of Integer Operations Created by Mr. Lafferty Maths Dept.

2. Starter Questions In pairs, write down the rules for integers giving examples for each. www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

3. Significant Numbers Level 4 Learning Intention Success Criteria • To know the meaning of significant number. • We are learning the term significant numbers for decimals and whole numbers. www.mathsrevision.com • Apply knowledge to problems.

4. Significant Numbers Level 4 • In mathematics a figure or digit is significant • if it gives an idea of both: • Quantity • Accuracy www.mathsrevision.com It is similar to rounding and all to do with zero’s

5. Significant Numbers Level 4 Decimal numbers What is the first rule? 0.04 1 significant figures 0.37 2 significant figures What is the second rule? 0’s at the beginning DON’T count 1.04 3 significant figures www.mathsrevision.com 0.306 3 significant figures What is the third rule? 0’s in the middle DO count 1.30 3 significant figures 0.90 2 significant figures 0’s a the end DO count

6. Significant Numbers Level 4 Easy rule : Just remember 0’s at the beginning DON’T count Exercise : Round to 2 sig figures 55.24 55 1.24 1.2 12.307 12 2.307 2.3 www.mathsrevision.com 0.08445 0.084 0.445 0.45 0.00106 0.0011 0.0162 0.016 0.030467 0.030 0.003398 0.0034 0.0503990 0.050 0.0103290 0.010

7. Significant Numbers Level 4 Whole Numbers What is the rule 106 3 significant figures 0’s in the middle DO count 9087 4 significant figures 360 ? 2 / 3 significant figures www.mathsrevision.com 0’s at the end MAY or MAY NOT count depending on the question. There are 360 degrees in a circle. 3 significant figures 2 significant figures 358 to the nearest ten is 360.

8. Significant Numbers Level 4 Easy rule : 0’s at the end MAY or MAY NOT count Exercise : Round to 2 sig figures 55 55 15030 15000 1094 1100 230 230 www.mathsrevision.com 445 450 17693 18000 50298 50000 135 140 10000 10000 1378409 1400000 314 310 1155 1200

9. Significant Numbers Level 4 Now try TJ 4+ Ex 1.1 Ch1 (page 6) www.mathsrevision.com

10. Starter Questions In pairs, write down as many are formulae as you know for different shapes. www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

11. Estimating Level 4 Learning Intention Success Criteria • Be able to round a number to any significant figure. • We are learning to use significant numbers to estimate values for calculations. www.mathsrevision.com • Apply knowledge to calculations to estimate values.

12. Whole Numbers Using Rounding to Estimate Answers Level 4 It is very important when solving problems that we have a rough idea of the answer we are expecting. Example : Mentally estimate the answer to 42 x 49 Easiest way, is to round the two numbers to 1 sig. Fig. www.mathsrevision.com 40 x 50 = 400 x 5 = 2000 Created by Mr. Lafferty Maths Dept.

13. Whole Numbers Using Rounding to Estimate Answers Level 4 Example : Mentally estimate the answer to 104 x 19 Easiest way, is to round the two numbers to 1 sig. Fig. 100 x 20 = 1000 x 2 = 2000 www.mathsrevision.com Example : Mentally estimate the answer to 878 ÷ 27 Easiest way, is to round the two numbers to 1 sig. Fig. 900 ÷ 30 = 90 ÷ 3 = 30 Created by Mr. Lafferty Maths Dept.

14. Significant Numbers Level 4 Now try TJ 4+ Ex 1.2 Ch1 (page 7) www.mathsrevision.com

15. Starter Questions www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

16. Order of Operation BODMAS Learning Intention Success Criteria • To understand what BODMAS means. • 1. We are learning the order of doing calculations. • 2. To be able to do calculations in the correct order. www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

17. Order of Operation BODMAS Priority - Brackets B O D M A S - Other “of” means x } - Division Same - Multiplication www.mathsrevision.com } - Addition Same - Subtraction Created by Mr. Lafferty Maths Dept.

18. Order of Operation BODMAS -6 + 15 x 3 1 + 4 x 5 = -6 + 5 = 1 + 20 = -1 = 21 www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

19. Order of Operation BODMAS (2x4) + (13-9) 135 ÷(29-26) = 8 + 4 = 135 ÷ 3 = 12 = 45 www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

20. Order of Operation BODMAS Put in brackets to make calculation right. 10 ÷ 5 – 3 + 7 = 12 ( ) ( ) 2 + 8 x 3 – 7 + 2 =21 www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

21. Order of Operation BODMAS Calculate 10 ÷ 5 – 3 + 7 = 12 ( ) www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

22. Order of Operation Is half of two plus two equal to two or three? www.mathsrevision.com Three. It seems that it could almost be either,but if you follow the mathematical orders of operation,division is performed before addition. So... half of twois one. Then add two, and the answer is three.

23. What is twice two thirds of three quarter of 10. Order of Operation 10 ! www.mathsrevision.com www.mathsrevision.com

24. Order of Operations Now try 4+ Ex 1.3 Ch1 (page 8) www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

25. Starter Questions www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

26. Integers Learning Intention Success Criteria 1. Understand and be able to use rules to calculate values. • 1. We are revising rules for integers. www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

27. Integers (-6) - 8 = -14 5 + (-2) = 5 – 2 = 3 (-7y) – (-3y) = -7y + 3y = -4y (-8e) + 17e = 9e www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

28. Integers (-6) x (-8) = 48 5w2 – ( -4w2) = 5w2 + 4w2 = 9w2 (-5)2 – (-3)2 = 25 - 9 = 16 (-21e) ÷ 3e = -7e www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

29. Order of Operations Now try 4+ Ex 1.4 Ch1 (page 9) www.mathsrevision.com Created by Mr. Lafferty Maths Dept.