Question

84
x 53

53
x 34

64
x 40

89
x 11

88
x 60

24
x 48

33
x 26

90
x 52

11
x 85

62
x 23

10
x 65

99
x 68

Explanation:

Step1: Calculate 84×53

$84\times53=(80 + 4)\times53=80\times53+4\times53=80\times(50 + 3)+4\times(50+3)=80\times50+80\times3+4\times50+4\times3=4000+240 + 200+12=4452$

Step2: Calculate 53×34

$53\times34=(50 + 3)\times34=50\times34+3\times34=50\times(30 + 4)+3\times(30 + 4)=50\times30+50\times4+3\times30+3\times4=1500+200+90 + 12=1802$

Step3: Calculate 64×40

$64\times40=(60 + 4)\times40=60\times40+4\times40=2400+160=2560$

Step4: Calculate 89×11

$89\times11=(90 - 1)\times11=90\times11-1\times11=990-11=979$

Step5: Calculate 88×60

$88\times60=(80 + 8)\times60=80\times60+8\times60=4800+480=5280$

Step6: Calculate 24×48

$24\times48=(20+4)\times48=20\times48 + 4\times48=20\times(40 + 8)+4\times(40 + 8)=20\times40+20\times8+4\times40+4\times8=800+160+160+32=1152$

Step7: Calculate 33×26

$33\times26=(30 + 3)\times26=30\times26+3\times26=30\times(20 + 6)+3\times(20 + 6)=30\times20+30\times6+3\times20+3\times6=600+180+60+18=858$

Step8: Calculate 90×52

$90\times52=90\times(50 + 2)=90\times50+90\times2=4500+180=4680$

Step9: Calculate 11×85

$11\times85=(10 + 1)\times85=10\times85+1\times85=850+85=935$

Step10: Calculate 62×23

$62\times23=(60 + 2)\times23=60\times23+2\times23=60\times(20 + 3)+2\times(20 + 3)=60\times20+60\times3+2\times20+2\times3=1200+180+40+6=1426$

Step11: Calculate 10×65

$10\times65 = 650$

Step12: Calculate 99×68

$99\times68=(100 - 1)\times68=100\times68-1\times68=6800-68=6732$

Answer:

$84\times53 = 4452$, $53\times34=1802$, $64\times40 = 2560$, $89\times11=979$, $88\times60=5280$, $24\times48=1152$, $33\times26=858$, $90\times52=4680$, $11\times85=935$, $62\times23=1426$, $10\times65=650$, $99\times68=6732$