Ten, eleven, twelve, . . .
Twenty, twenty one, twenty two, . . .
Ten books plus seven books equals . . .
Seventeen, sixteen, fifteen, . . .
Ten plus seven equals . . .
Twenty, nineteen, eighteen, . . .
Twenty eight minus twelve equals . . .
Twenty pencils minus thirteen pencils equals . . ...
Thirteen plus twelve equals . . .
Thirty minus sixteen equals . . .