The main idea behind area model is to crack multiplication of 2 larger numbers in sum of several easier to calculate multiplications of smaller numbers. Each multiplication of those smaller numbers is represented by part of the area in the picture.
So, we can write down number 34 as sum of 30 and 4 and number 17 as sum of 10 and 7.
Going further we can write down:
34*17=(30+4)*(10*7)=30*10+30*7+4*10+4*7=578
So, we can write down number 34 as sum of 30 and 4 and number 17 as sum of 10 and 7.
Going further we can write down:
34*17=(30+4)*(10*7)=30*10+30*7+4*10+4*7=578