L.O.1 To be able to use known facts and place value to multiply and divide mentally

1. L.O.1 To be able to use known facts and place value to multiply and divide mentally

2. 0 We are going to count in steps of 0.6

3. 0.6 x 1 = 0.6 6 x 1 = 6 0.6 x 2 = 1.2 6 x 2 = 12 0.6 x 3 = 1.8 6 x 3 = 18 0.6 x 4 = 2.4 6 x 4 = 24 NOTICE that 0.6 is ten times smaller than 6

4. Q. What is 0.6 x 9? The answer will be 10 times smaller than 6 x 9

5. We will do some RAPID MENTAL CALCULATIONS using 0.6 and 6

6. L.O.2 To be able to extend written methods to multiplication of HTU x U and U.t x U

7. 258 x 9 Estimate = 258 x 10 = 2580 BUT this will be “out” by 258. Estimates made when multiplying are often not as close as those done when adding or subtracting. Q. If 258 x 10 = 2580 how elsecould we have calculated 258 x 9?

8. 258 x 9 1800 450 72 2322 Q. Where do you think 1800, 450, 72 and 2322 have come from?

9. 258 x 9 1800 = 200 x 9 450 = 50 x 9 72 = 8 x 9 2322 = 1800 + 450+ 72 It’s easy really!

10. Look at this one: 473 x 9 473 x 9 3600 630 27 4257

11. Look at this one: 473 x 9 473 x 9 3600 = 400 x 9 630 = 70 x 9 27 = 3 x 9 4257 = 3600 + 630 + 27

12. Try these. Use BOTH layouts for the first three and your preferred layout for the last two. Remember to approximatefirst. 254 x 6 378 x 9 254 x 5 872 x 9 746 x 6

13. LOOK… 258 x 9 18 45 72 135 Q. Can the answer possibly be right? What is wrong?

14. Here the answer Here the answer figures are in figures are in the wrong place. the right place. 258 258 x 9 x 9 18 18 - - 45 45 - 72 72 135 2322 The PLACE VALUE of the figures is VITAL.

15. Yesterday we did 5.7 x 6 How could we lay this out vertically as we did for some of our calculations today?

16. We need to think carefully about where the figures go ….. PLACE VALUE 5.7 x 6 30 4.2 34.2 Here we need to ALIGN the DECIMAL POINTS

17. By the and of the lesson the children should be able to: Develop an efficient standard method that can be applied generally, approximating first.