1 / 20

SELE first Maths Calculation Guide May 2012

SELE first Maths Calculation Guide May 2012. +10. +10. +10. +10. +7. 76. 96. 106. 116. 123. 86. + 40. + 7. 116. 123. 76. Addition Strategies – Blank Number Lines. Jumps along the number l ine go above when adding by counting on from the higher number. 76 + 47.

cutter
Download Presentation

SELE first Maths Calculation Guide May 2012

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SELEfirst Maths Calculation Guide May 2012

  2. +10 +10 +10 +10 +7 76 96 106 116 123 86 + 40 + 7 116 123 76 Addition Strategies – Blank Number Lines Jumps along the number line go above when adding by counting on from the higher number 76 + 47 76 + 47 = 123

  3. Addition Strategies–Using Partitioning 76 + 47 = ? 70 + 40 = 110 6 + 7 = 13 110 + 13 = 123

  4. 358 + 473 358 + 473 831 1 1 Addition Strategies – Vertical Methods 358 + 473 = ? 11 120 700 Condensed (Traditional) Method– teach adding values of the columns (e.g. 300 + 400 = 800) 831 Column Method

  5. 19 20 23 33 43 -1 -3 -10 -10 Subtraction Strategies – Blank Number Lines Jumps along the number line go underneath when subtracting by counting back from the higher number 43 – 24 = ? 43 – 24 = 19

  6. +30 +5 90 55 60 Subtraction Strategies – Blank Number Lines Counting on from the lower number to the higher number to find the difference 93 – 55 = ? +3 93 93 – 55 = 38

  7. Subtraction Strategies – Blank Number Lines This method can be used for decimals too 8.23 – 4.55 = ? +3 +0.23 +0.45 4.55 5.00 8.00 8.23 8.23 – 4.55 = 3.68

  8. Subtraction Strategies – Partial Calculations 362 300 60 2 147 100 40 7 362 300 60 2 147 100 40 7 50 5 Same value, different appearance 1 1

  9. Subtraction takes many forms! • Find the difference between.... • How many more to make ..... • How much change from ... • There are 19 fewer .... • What is 19 less than .....

  10. The importance of inverses + - • Spotting families of numbers • Use one method to check the other • Number triangles 7 + 3 4

  11. Multiplication Strategies – Grid Method 47 x 8 = ? x 40 7 8 320 56 376 47 x 8 = 376

  12. Multiplication Strategies – Grid Method 37 x 46 = ? x 307 40 1200 280 6 180 42 1380 322 1380 + 322 1702 1 37 x 46 = 1702

  13. Division Strategies • Sharing 32÷ 4 = 8 (32 shared between 4) • Grouping 32÷ 4 = 8 (32 put into groups of 4)

  14. Division Strategies - Partitioning 72 ÷ 5 = ? 72 50 22 10 4 r2 72 ÷ 5 = 14 r2

  15. Division Strategies - Chunking Method 87 ÷ 7 Easy chunks to think about: x10 = 70 x5 = 35 x2 = 14

  16. 87 ÷ 7 = ? Division Strategies - Chunking Method 7 87 70 (7x10) 17 14 (7x2) 3 Add the chunks (groups of 7) to solve Shown in red The remainder is what is left at the bottom. Shown in blue Subtract chunks of the divisor (7 in this example) to get to, or close to, zero 87 ÷ 7 = 12 r3

  17. Division Strategies - Blank Number Lines 87 ÷ 7 can also be done on a number line 3 17 87 -14 subtract 7x2 or 7 twice -70 subtract 7x10 or 7 ten times We have subtracted seven 12 times and have 3 left so… 87 ÷ 7 = 12 r 3

  18. The importance of inverses x ÷ • Spotting families of numbers • Use one method to check the other • Number triangles 12 x 3 4

  19. Inverse operations • 950.4 ÷ = 49.5 950.4 49.5 x

  20. Linking areas of Maths Division is very strongly linked to • FRACTIONS • Relationships • Decimals (a type of fraction) • Effect of x and ÷ by 10 and 100 • Percentages (a type of fraction) ¼

More Related