Select the proper placement for parentheses to speed up the addition for the expression 2 + 9 + 8 + 1 A. (1 + 2) + (9 + 8) B. (9

Question

3 years ago

9

+ 2) + (8 + 1) C. (8 + 2) + (9 + 1) D. (8 + 9) + (2 + 1)

2 answers:

Semmy [17] · Answer 1 · 2022-07-12T04:35:29+03:00

Semmy [17]3 years ago

7 0

The correct answer is c.

GenaCL600 [577] · Answer 2 · 2022-07-12T02:35:20+03:00

Answer: (8+2)+(9+1)

Step-by-step explanation:

Given expression : $2+9+8+1$

To speed up the addition for the expression, we need to make ten such that addition become more easier.

Here we can make groups of numbers such that their sum will be 10.

So we combine 8 and 2 in a parentheses and 9 and 1 in another.

Thus, the given expression will look like

$(8+2)+(9+1)$

$=(10)+(10)=20$