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=12x=20-12x=820-8=122) 20-x=14x=20-14x=620-6=14