1. Year 7 Order of Operations Dr J Frost (jfrost@tiffin.kingston.sch.uk) www.drfrostmaths.com Last modified: 13 th September 2015 Objectives: Appreciate that in maths we evaluate operations in a particular order (according to BIDMAS). Be able to use a calculator to evaluate more complicated expressions.

2. Starter Type each of these into calculator and see what result you get. Why are they different. What is the calculator doing in each case? There’s two operations in each case: negating (i.e. making something negative) and squaring. The two are ordered differently in each example. How do we determine the order?

3. BIDMAS What is the precedence of the operators? (i.e. the order we do the operations in)  Do what first ? Then ? Brackets Precedence Indices Division Multiplication Addition Subtraction Includes negation You can remember this as “BI[DM][AS]”

4. BIDMAS Brackets Precedence Indices Division Multiplication Addition Subtraction If we want to do “minus 3, squared”. Why do we need the brackets then? The brackets forces the negation to be done before the squaring, as otherwise (by BIDMAS) the power would be done first. Which is the correct answer? 1915 If with have multiple operations with the same precedence, we evaluate left-to-right. 20 – 3 + 2 ?

5. Quickfire Questions Evaluate the following (and optionally also suggest a stupid answer!) Brackets Precedence Indices Division Multiplication Addition Subtraction ? ? ? ? ? ? ? ? ? ?

6. Test Your Understanding i ii iii ? ? ?

7. Exercise 1 1 a b c d e f 2 a b 3 4 5 6 7 8 9 10 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? a b c d ? ? ?

8. Year 7 Calculator Use Dr J Frost (jfrost@tiffin.kingston.sch.uk) www.drfrostmaths.com

9. Using a Calculator

10. Starter A B C ? ? ? Bro Tip: Since the outermost thing is a fraction, press the fraction key first. Use direction keys to move around.

11. Modifying Existing Expressions ?

12. Have a Go… ? ? ? A B C

13. More on using the ANS key. Square your answer. Subtract your answer from 1000. Square root your answer. ? ? ? ?

14. Cube Root ? ? ? ?

15. REDORANGEGREENBLUE Use your diary coloured cards to vote for the correct answer in each question. (Use the front of your diary for blue)

20. Remember you can use the arrow and DEL keys to modify an existing calculation.

21. (Interesting Fact: This calculation will give you the ‘golden ratio’)

23. Exercise 2 Calculator Fun! 12 a b c d e f g ? ? ? ? ? ? ? ?