Find 548+224 mentally by making a ten .Put the steps in order 550+22=572224=2+22+200548+2=550572+200=772

Organizing the steps, we have:
First Step: 224 = 200 + 22 + 2
Second Step: 548 + 2 = 550
Third Step: 550 + 22 = 572
Fourth Step: 572 + 200 = 772