First write the numbers by place value: 74 = 70 + 4 and 56 = 50 + 6. Next we would like to subtract by place value, but 6 is greater than 4. So, we can rewrite 70 + 4 as 60 + 14, taking one ten and regrouping it as 10 ones. Now we can subtract the tens: 60 - 50 = 10, and then the ones: 14 - 6 = 8. 10 + 8 = 18, so 74 - 56 = 18.