Level 2 3 Numeracy Parent Engagement Evenings Multiplication
- Slides: 29
Level 2 / 3 Numeracy Parent Engagement Evenings
Multiplication • Times Tables • Multiplying by 10, 1000 etc. • Multiplying by multiples of 10, 1000 etc. • Long multiplication
Times Tables There are no tricks to this (well sort of…), we just need to learn them! There are LOTS of tools to help with times tables fluency
Times Tables Don’t give in, give them strategies! Trying to work out 6 x 7… Do you know, 6 x 5? use repeated addition Exposure to problematic ones
Multiplying by 10, 1000 etc. “ just add on the zero’s” We use our place value number line Hundreds Tens Ones . Tenths Hundredths Thousandths
Multiplying by 10, 1000 etc. 46 x 10 Hundreds Tens Ones 4 6 0 . Tenths Hundredths Thousandths
Multiplying by 10, 1000 etc. 1. 3 x 100 Hundreds Tens Ones . 1 . 0 Tenths 3 0 Hundredths Thousandths
Multiplying by multiples of 10, 1000 etc. 12 x 2000 Ten Thousands 12 x 1000 12 x 2 = 24 24 x 1000 Hundreds 0 Tens Ones 2 0 4 0 . Tenths
Multiplying by multiples of 10, 1000 etc. I want to come back to this a bit later to complete some more challenging examples, we just need to see some other things first…
Long Multiplication There are many strategies for long multiplication. Some lend themselves to understanding, some do not. However they all produce an answer. It’s getting the right one that works for you!
Long Multiplication – The ‘Grid’ Method 45 x 7 280 + 35 1 31 5 7 40 5 280 35
Long Multiplication – The ‘Grid’ Method 23 x 19 200 180 30 + 27 1 4 37 20 3 10 200 30 180 27 9
Long Multiplication – The ‘Grid’ Method 238 x 56 200 50 6 30 8
Long Multiplication – The ‘Grid’ Method 70 5 30 2100 150 6 420 30 7. 5 75 x 36 + 2100 150 420 30 1 27 0 0
7. 5 x 36 7. 5 has one decimal place Using estimation. . 36 has zero decimal places roughly 8 x 40 = 320 1+0=1 so 2700 must change to 270. 0 le ru r e h The answer must have not A one decimal place 270. 0 Understanding of number llow o f to Only works for multiplication We multiplied 7. 5 by 10 to make it 75 We must now divide our answer by 10 to correct the change we made at the beginning
Long Multiplication – The ‘Grid’ Method 68 x 7 32 x 95 1. 7 x 48 476 3040 81. 6
Long Multiplication – Napier’s Bones 8 9 x 85 7 5 4 tens 2 5 ones 7 6 765 ones 5 9
Long Multiplication – Napier’s Bones 4 47 x 68 2 1 3196 4 7 4 2 5 3 2 3 1 9 6 6 6 8
Long Multiplication – Napier’s Bones 214 x 3. 2 3 2 2 1 4 3 2
2 0 6 3 0 8 2 4 6 1 0 0 0 4 1 4 3 214 x 32 = 6848 2 8 214 x 3. 2 = 684. 8
Long Multiplication – ‘chimney’ sum 39 x 8 85 x 64 26 x 3. 8 312 5440 98. 8
Long Multiplication – ‘Chimney’ sum 36 x 8 3 6 24 + 4 x 8 2 8 8
Long Multiplication – ‘Chimney’ sum 97. 8 x 7 9 7 8 63+ 5 49+ 5 x 7 6 8 4. 6
Long Multiplication – ‘Chimney’ sum 42 x 68 60 x 3 2 5 2 8 4 2 32+1 24+1 6 3 2 5 8 6 0 6
Long Multiplication – ‘Chimney’ sum 3. 8 x 2. 1 20 3 8 x 2 3 7 6 7. 9 1 8 0 8 6+ 1
Long Multiplication – ‘Chimney’ sum 29 x 5 37 x 28 12. 3 x 1. 8 145 1036 22. 14
Multiplying by multiples of 10, 1000 etc. 38 x 500 38 x 5 by your preferred method 30 38 x 5 8 3 8 5 5 190 x 100 Ten Thousands Hundreds 1 Tens 9 0 Ones 0 0 . Tenths
Multiplying by multiples of 10, 1000 etc. 28 x 50 3. 8 x 400 253 x 8000 1400 1520 2, 024, 000
Thank you, see you on the 24 th May
