Do the sums
1) Eleven plus seven is . . .
2) Eight plus eight is . . .
3) Twelve minus six is . . .
4) Fourteen minus two is . . .
5) Five plus six is . . .
6) Fifteen plus five is . . .
7) Twenty minus five is . . .
8) Sixteen minus three is . . .
9) Thirteen plus six is . . .
10) Three plus five is . . .
Now check
1) eighteen
2) sixteen
3) six
4) twelve
5) eleven
6) twenty
7) fifteen
8) thirteen
9) nineteen
10) eight