How do you do proper form and improper form of a 5 digit #

Question

(5x10,000)+(14x1000)+(7x100)+(1x10)+(2x1)=

{a}...(5x10000)+(4x1000)+(8x100)+(5x10)+(2x1)

{b}...(6x10000)+(10x1000)+(7x100)+(5x10)+(2x1)

{c}...(15x10000)+(4x1000)+(7x100)+((5x10)+(2x1)

{d}...(6x10000)+(4x1000)+(7x100)+(5x10)+(2x1)

Answer 1

When you add up the numbers you get 50000+14000+700+10+2=64712. However I think the tens figure should have been 5*10 not 1*10, otherwise the answer is none of (a) to (d). If this adjustment is made the number is 64752. So answer d would be the right one. Note how the thousands figure spills over into the ten-thousands. Answer d is the proper form for the number because we need to have a number between 0 and 9 in the (thousands, or any) column, and 14 is bigger than 9.