MATHS

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