No more borrowing and paying back, or the new alternative
Use addition and then simple subtraction, naturally there are several steps
Example 234 – 187
234
-187 (should be lined up!)
Now 7 is greater than 4, so we add 3 to both numbers, giving a zero in the units position of the second number
234 -187 = 237 – 190 (must be able to add 3 to 187 !!!)
moving to the 10’s position, and very formally, 90 is greater than 37 so add 10 to both numbers, giving
237 – 187 = 247 – 200, which is now simple, with result 47
Of course, if the lower digit is less than the one above just subtract it from each number
234 – 117 = 237 – 120 = 214 – 100 = 114
It is best to keep the “one above the other” layout, but I have fought with the editor enough today.