2357 x 62 = 2357 x 31 x 2
= (2000x31+300x31+50x31+7x31) x 2
= (60000+2000+9000+300+(500x3+50)+210+7) x2
= (62000+9300+1550+217) x2
= (70000+1300+1550+217) x2
= 2(71300+1550+217)
= 2(72500+550+17)
= 2(72500+567)
= 2(72500+500+60+7)
= 2(73000+60+7)
= 2(73067)
= 2 x 73067
= 70000x2+3000x2+60x2+7x2
= 140 000+6 000+120+14
= 146 000+134
= 146 134
3985 x 96 = 3985 x 48 x 2
= 3985 x 24 x 2 x 2
= 3985 x 12 x 2 x 2 x 2
= 3985 x 6 x 2 x 2 x 2 x 2
= 3985 x 3 x 2 x 2 x 2 x 2 x 2
= (3000x3+900x3+80x3+5x3) x 2 x 2 x 2 x 2 x 2
= (9000+2700+240+15) x 2 x 2 x 2 x 2 x 2
= (11700 + 255) x 2 x 2 x 2 x 2 x 2
= 11955 x 2 x 2 x 2 x 2 x 2
= (11 000x 2+900x2+50x2+5x2) x 2 x 2 x 2 x 2
= (22 000+1800+100+10) x 2 x 2 x 2 x 2
= (23800+110) x 2 x 2 x 2 x 2
= 23910 x 2 x 2 x 2 x 2
= (23 000x2+900x2+10x2) x 2 x 2 x 2
= (46000+1800+20) x 2 x 2 x 2
= 47820 x 2 x 2 x 2
= (40000x2+7000x2+800x2+20x2) x 2 x 2
= (80000+14000+1600+40) x 2 x 2
= (94000+1640) x 2 x 2
= 95 640 x 2 x 2
= (95000x2+600x2+40x2) x 2
= (190 000+1200+80) x 2
= 191 280 x 2
= 100 000x2+90 000x2+1 000x2+200x2+80x2
= 200 000+180 000+2000+400+160
= 380 000+2560
= 382 560 
Don't confuse the PSLE maths students leh.
By the way, PSLE maths students will solve Q1(a) by making the
numerators to be the same hor ie 2/5 = 6/15 and 3/4 = 6/8 and
the ratio of paul's height to
the total height of his father and Sean = 6 : 15 + 8 = 6 :
23. This type of question is
commonly asked in PSLE maths and this method is found in many of
the PSLE maths assessment guidebooks lor.
For question 2, PSLE maths students do not learn expansion and
solve for x lah.
It can be solved by using the bar model lah.
l
70% of
original
l 30% of original l
l $990 - DVD Player l 55% of R - sofa l 45% of R -
left l