8 15 16
1.8966-6698=
16-8=8
150-90=60
800-600=200
8000-6000=2000
2000+200+60+8=2268
5 13 5 14
2.6364-5656=
14-6=8
50-50=0
1300-600=700
5000-5000=0
700+0+0+8=708
I am a Year 8 student at Glenbrae School in Auckland, NZ. I am in Room 7 and my teachers are Mrs Tofa and Mrs Raj.
PROBLEM
|
Strategy
|
Answer
|
|
90x50=4500
90x40=3600
4500+3600=8100
5x90=450
8100-450=
|
7650
|
2.79x89=
|
80x40=3200
80x40=3200
3200+3200=6400
80x9=720
6400+720=7120
1x89=89
7120-89=
|
7031
|
3.68x76=
|
70x50=3500
70x20=1400
70x6=420
3500+1400+420=5320
2x76=152
5320-152=
|
5168
|
4.92x88=
|
100x40=4000
100x40=4000
4000+4000=8000
100x8=800
8000+800=8800
8x88=704
8800-704=
|
8096
|
5.59x67=
|
60x30=1800
60x30=1800
60x7=420
1800+1800+420=4020
1x67=67
4020-67=
|
3953
|
PROBLEM
|
Strategy
|
Answer
|
1.28x9
|
30x5=150
30x4=120
150+120=270
2x9=18
270-18=
|
252
|
2. 59x15=
|
60x10=600
60x5=300
600+300=900
1x15=15
900-15=
|
885
|
3. 43x7=
|
50x2=100
50x5=250
250+100=350
7x7=49
350-49=
|
301
|
4.81x9=
|
90x4=360
90x5=450
360+450=810
9x9=81
810-81=
|
729
|
5.62x17=
|
70x10=700
70x7=420
700+420=1120
8x17=136
1120-136=
|
974
|
6.39x15=
|
40x10=400
40x5=200
400+200=600
1x15=15
600-15=
|
585
|
7.87x9=
|
90x4=360
90x5=450
360+450= 810
3x9=27
810-27=
|
783
|
8.67x33=
|
70x30=2100
70x3=210
2100+210=2310
3x33=99
2310-99=
|
2211
|
9. 63x7=
|
70x2=140
70x5=350
140+350=490
7x7=49
490-49=
|
441
|
10.75x9=
|
80x5=400
80x4=320
400+320=720
5x9=45
720-45=
|
675
|
11.55x10=
|
60x5=300
60x5=300
300+300=600
5x10=50
600-50=
|
550
|
12.92x9=
|
100x5=500
100x4=400
500+400=900
8x9=72
900-72=
|
828
|
13.53x8=
|
60x4=240
60x4=240
240+240=480
7x8=56
480-56=
|
424
|
15.41x9=
|
50x5=250
50x4=200
200+250=450
9x9=81
450-81=
|
369
|
16.72x7=
|
80x2=160
80x5=400
160+400=560
8x7=56
560-56=
|
504
|
17.91x8=
|
100x4=400
100x4=400
400+400=800
9x8=72
800-72=
|
728
|
18.33x9=
|
40x4=160
40x5=200
160+200=360
7x9=63
360-63=
|
297
|