Hi, this is some of my learning this week. I learnt how to add and subtract using doubling and halving. I found this strategy really helpful.
WALT :add or subtract multiplication questions
- If 9 × 20 = 180 what is 9 × 21 ? 189
- If 8 × 30 = 240 what is 8 × 31 ? 248
- If 4 × 40 = 160 what is 4 × 42 ? 168
- If 5 × 50 = 250 what is 5 × 51 ? 255
- If 3 × 60 = 180 what is 3 x 62 ? 196
- If 2 × 70 = 140 what is 2 × 73 ? 146
- If 4 × 80 = 320 what is 4 × 82 ? 328
8) If 2 × 90 = 180 what is 2 × 94 ? 188
Exercise 2
What to do
Use the information given to you to derive the answer to a similar problem.
1) If 9 × 20 = 180 what is 9 × 19 ? 171
2) If 8 × 30 = 240 what is 8 × 29 ? 232
3) If 7 × 40 = 280 what is 7 × 39 ? 273
4) If 5 × 50 = 250 what is 5 × 49 ? 245
5) If 3 × 60 = 180 what is 3 × 58 ? 174
6) If 2 × 70 = 140 what is 2 × 67 ? 134
7) If 4 × 80 = 320 what is 4 × 78 ? 312
8) If 2 × 90 = 180 what is 2 × 86 ? 172
Exercise 3
What to do
Use the information given to you to derive the answer to a similar problem.
- If 9 × 20 = 180 what is 9 × 22 ? 198
- If 7 × 30 = 210 what is 7 × 32 ? 224
- If 5 × 40 = 200 what is 5 × 43 ? 215
- If 4 × 50 = 200 what is 4 × 51 ? 204
- If 3 × 60 = 180 what is 3 × 61 ? 183
- If 6 × 70 = 420 what is 6 × 73 ? 438
- If 6 × 80 = 480 what is 6 × 81 ? 486
8) If 8 × 90 = 720 what is 8 × 92 ? 736
Exercise 4
What to do
Use the information given to you to derive the answer to a similar problem.
- If 9 × 20 = 180 what is 9 × 18 ? 172
- If 7 × 40 = 280 what is 7 × 37 ? 260
- If 5 × 40 = 200 what is 5 × 38 ? 190
- If 4 × 50 = 200 what is 4 × 47 ? 198
- If 3 × 60 = 180 what is 3 × 56 ? 168
- If 6 × 70 = 420 what is 6 × 67 ? 402
- If 6 × 80 = 480 what is 6 × 78 ? 466
8) If 8 × 90 = 720 what is 8 × 88 ? 704
Exercise 5
What to do
Use the information given to you to derive the answer to a similar problem.
- If 4 × 200 = 800 what is 4 × 201 ? 804
- If 7 × 300 = 2100 what is 7 × 301 ? 2107
- If 8 × 400 = 3200 what is 8 × 402 ? 3216
- If 9 × 500 = 4500 what is 9 × 501 ? 4509
- If 5 × 600 = 3000 what is 5 × 602? 3010
- If 3 × 700 = 2100 what is 3 × 704 ? 2112
- If 2 × 800 = 1600 what is 2 × 803 ? 1606
8) If 6 × 900 = 5400 what is 6 × 903 ? 5418
Exercise 6
What to do
Use the information given to you to derive the answer to a similar problem.
- If 4 × 200 = 800 what is 4 × 199 ? 796
- If 7 × 300 = 2100 what is 7 × 299 ? 2093
- If 8 × 400 = 3200 what is 8 × 398 ? 3184
- If 9 × 500 = 4500 what is 9 × 498 ? 4482
- If 5 × 600 = 3000 what is 5 × 597 ? 2985
- If 3 × 700 = 2100 what is 3 × 698 ? 2094
- If 2 × 800 = 1600 what is 2 x 797 ? 1594
- If 6 × 900 = 5400 what is 6 × 897 ? 5382
Exercise 7
What to do
Use the information given to you to derive the answer to a similar problem.
- If 2 × 25 = 50 what is 2 × 24 ? 43
- If 4 × 25 = 100 what is 4 × 27 ? 108
- If 3 × 15 = 45 what is 3 × 14 ? 42
- If 4 × 15 = 60 what is 4 × 17 ? 68
- If 6 × 15 = 90 what is 6 × 14 ? 84
- If 2 × 25 = 50 what is 2 × 26 ? 52
- If 4 × 25 = 100 what is 4 × 24 ? 96
- If 3 × 15 = 45 what is 3 × 16 ? 48
- If 4 × 15 = 60 what is 4 × 13 ? 52
- If 6 × 15 = 90 what is 6 × 17 ? 102
Exercise 8
What to do
Use the strategy add a little/subtract a little to solve these problems.
Julie wanted to find 3 × 28.
She knows that 28 is near 30, so she used 3 × 30 = 90 and subtracted 3 × 2 = 6 to get the answer.
Julie recorded this in her maths book
3 × 28 = 90 – 6 = 84
Using Julie’s method find the answer to the following problems. Record your working like Julie did.
1) 4 × 19 =76 (2) 3 × 41=123 (3) 5 × 59=295
4) 7 × 52 =364 (5) 4 × 73=292 (6) 3 × 37= 111
7) 6 × 102=612 (8) 5 × 301=1505 (9) 4 × 698=2792
10) 3 × 499=1497 (11) 7 × 602=4214 (12) 9 × 3999=35,991
These are my silly sentences for Word Work this week. I have used my spelling words this week to write some funny sentences.
Writing
We were given this picture to write about. Here are my answers. I learnt there are many types of storms in the world.
- Have you ever been caught in a storm? What was it like?
- Are storms the same all over the world, or are the different?
- What causes a storm?
- What do you think are the most dangerous things of a storm?
- How can people avoid these dangers?
- Do mountains play a part when storms build?
- Can you think of other occasions when weather can be dangerous?
- What is your favourite type of weather?
- If you could live anywhere in the world where would it be
- I was up at MT Cheeseman Sking and All this strong ,hard bits of snow it was scary
- I reckon no
- Nature
- Rain ,hail,ice,snow
- Stay at home and brace yourself
- no
- Snow
- New Zealand
