Make efficient use of subtraction strategies including column subtraction | Exit Quiz | Oak National Academy

Which calculations would it be most efficient to answer using a mental strategy?

• 302 − 297

• 763 − 481

• 783 − 200

• 742 − 337

Answer explanation

302 − 297 and 783 − 200 could both be calculated efficiently using a mental strategy.

Which calculations would it be most efficient to answer using column subtraction?

• 941 − 323

• 751 − 749

• 845 − 199

• 835 − 567

Answer explanation

It would be most efficient to calculate 941 − 323 and 835 − 567 using column subtraction.

Sam calculates 401− 396 by counting on from 396 He found a difference of ___.

Answer explanation

Sam found a difference of 5

Aisha wants to calculate 827 − 299 How should she calculate this using a mental strategy?

• Subtract 300 then subtract 1 more

• Subtract 300 then add 1

• Subtract 200 then subtract 1 more

• Subtract 200 then add 1

Answer explanation

To calculate 827 − 299, Aisha should subtract 300 then add 1 because she has subtracted 1 too many.

What is 555 − 199 = ___?

Answer explanation

555 − 199 = 356

Calculate 941 − 323 = ___

Answer explanation

941 − 323 = 618