Think of a Number N1/E2.3 Add and subtract two-digit whole numbers N1/E2.4 Recall addition and subtraction facts to 10. N1/E3.3 Recall addition and subtraction facts to 20 (but makes a good warm activity for any level) Kindly contributed to www.skillsworkshop.org by by Fiona Campbell fiona.campbell@cityofbristol.ac.uk City of Bristol College. N1/E2.3 Add and subtract two-digit whole numbers N1/E2.4 Recall addition and subtraction facts to 10. N1/E3.3 Recall addition and subtraction facts to 20 (but makes a good warm activity for any level) Kindly contributed to www.skillsworkshop.org by by Fiona Campbell fiona.campbell@cityofbristol.ac.uk City of Bristol College.

Think of a Number A bit of maths magic? Kindly contributed to www.skillsworkshop.org by by Fiona Campbell fiona.campbell@cityofbristol.ac.uk City of Bristol College. N1/E2.3 Add and subtract two-digit whole numbers N1/E2.4 Recall addition and subtraction facts to 10. N1/E3.3 Recall addition and subtraction facts to 20 (but makes a good warm activity for any level)

Think of a number between 1 and 10

Add 1

Double the result Hint: to double you by what?

Plus 5

Halve the result [Hint to halve something you divide by what. ] … Halve the result [Hint to halve something you divide by what?] …. Still not sure - then ask another student!

Add eight

Subtract 9

Subtract the number you first thought of

Your answer is 1 Try starting again with another number. Does it work for all numbers? Use big numbers and a calculator. How does it work?