Siz bu yerda saytimizda muntazam chop etilib kelinayotgan matematika fanidan 5-sinf o’quvchilariga mo’ljallangan «Olimpiada VIII tur» masalalari yechimlari va izohlari bilan tanishishingiz mumkin.
Javoblar:
1) Yechish: a1-a2=a3-a1, yoki 2a1=a2+a3; bundan 
2) Yechish:
(1+1000) +(2+999) +(3+998) + …=1001 ⋅500= 500500.
3) Yechish:
(2+1000):2⋅ 500=250500; (1+999):2 ⋅500= 250000;
250500:500=501; 250000:500= 500; 501-500=1;
Javob: Juft sonlar o’rta arifmetigi 1 ga katta.
4) Yechish:
36:(7-1)=6; Javob: 6 sekundda.
5) Yechish:
100-x-x=13; -2x=13-100; x=-87:(-2)=43,5; 100-43,5=56,5;
Javob: 43,5 sm; 56,5 sm.
6) Yechish:
n+(n+1)= 1001; 2n= 1000; n= 500; Javob: 500; 501.
7) Yechish:
1+2+3+4+5+6+7+8+9=45 ga egamiz.Bu yig’indidan 40 ni hosil qilish uchun qandaydir + larni – ga almashtirishimiz kerak.Ammo bitta” +” ni “–“ ga almashtirilganda yig’indi ishorasi almashtirilgan sonni ikki baravari miqdorida kamayadi.Ikkinchi tomondan juft songa kamayadi.Demak, 45 dan juft sonni ayirsak juft son hosil bo’lmaydi.Javob: Mumkin emas.
8) Yechish:
Ixtiyoriy uchta butun sondan albatta ikkitasi yoki juft yoki toq sonlar bo’ladi.Ularning yig’indisi esa 2 ga bo’linadi.
9) Javob: 745.
10) Yechish:
Masala shartiga ko’ra 9+n 999=9999; 999n=9990; n=10; Javob: 10 marta.
