Teaching informal and formal written methods for subtraction but tired of just lists of calculations? Look no further! Included in this package are 28 task cards each with 2 spot the mistake tasks to engage, enrich and extend understanding of column addition methods for TU-TU, HTU-HTU and decimals in the context of money.
There are 8 tasks for each type of method so work can differentiated across the class depending on their ability and understanding of the different written methods. They could also be used in conjunction with manipulatives and resources.
8 calculations for each method, 2 on each sheet. Each calculation has an error – incorrect subtraction, amounts not exchanged to the next column or carried to the next column but then not written down etc. Students can identify what is the error, explain clearly the mistake and suggest advice as if they were the teacher. Finally the correct calculation can be written.
The different methods include:
TU-TU expanded method (no exchanging to the next column)
TU-TU expanded method (with exchanging to the next column)
HTU-HTU expanded method (with some exchanging to the next columns)
HTU-HTU compact column subtraction (without exchanging)
HTU-HTU compact column subtraction (with 1 digit exchanging)
HTU-HTU compact column subtraction (with 2 digits exchanging)
U.th+U.th compact column subtraction in the context on money (8 using £ and 8 using $)
The task cards have been made with black line so that they are easy to photocopy and use.
They could be enlarged for those who need more space for their writing.
They could be used as an activity for individuals or students could work in a group of 4 and each complete the first box and then pass to the person on their left, complete the next section and pass again until all the sections are completed. The first box could be used just on its own and students just spot the mistake and write the correct answer in their books – the possibilities are endless!
Answers are included.
Error Analysis / Spot the Mistake task Cards for Written Addition Methods
Error Analysis / Spot the Mistake Task Cards for Written Multiplication Methods