Question

Several properties are used to evaluate this expression. Identify the property used in each step.

21 + (36 + 0 + 19)

21 + (36 + 19):


21 + (19 + 36):


(21 + 19) + 36:


40 + 36

76

Answer 1

Given expression: 21 + (36 + 0 + 19)

Using identity property of addition: a + 0 = a

21 + (36 + 0 + 19) = 21 + (36 + 19)

Using commutative property of addition: a + b = b + a

21 + (36 + 19) = 21 + (19 + 36)

Using associative property of addition: a + (b + c) = (a + b) + c

21 + (19 + 36) = (21 + 19) + 36

Now, add two numbers inside the bracket.

(21 + 19) + 36 = 40 + 36

Using closure property of addition: a + b = c any number.

40 + 36 = 76

Hence 21 + (36 + 0 + 19) = 76.