20 soni ichida arifmetik masala va misollar 1. Salimada 14 ta qalam bore di. Do’kondan yana 5 ta qalam oldi. Salimada jami nechta qalam bo’ldi? (yechish: 14+5=19) 2. Sinfda jami 8 ta o’gil bola bor. Qizlar esa o’g’il bolalardan 4 ta ko’p. Sinfda nechta qiz bolalar bor? Sinfda jami nechta bolalar bor? (yechish: 8+4=12, 8+12=20) 1) 20-x=12 x=20-12 x=8 20-8=12 2) 20-x=14 x=20-14 x=6 20-6=14