standard_description: Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.
problem_activity: Task
Decide if the equations are true or false. Explain your answer.
$2+5 = 6$
$3 + 4 = 2 + 5$
$8 = 4 + 4$
$3 + 4 + 2 = 4 + 5$
$5 + 3 = 8 + 1$
$1 + 2 = 12$
$12 = 10 + 2$
$3 + 2 = 2 + 3$
$32 = 23$


aligns: no