Question

Mina asked four friends to explain how each one solved the expression . Here are their explanations:

Answer 1

Ok let me answer this question by finding it's solution first.

The two numbers are 15.75 and 176.3

First we will compare the numbers.

1. A=176.3

2. B=15.75

one's place of A is greater than once place of B.

tens place of A is greater than tens place of B.

Hundred place of A is greater than hundred place of B.

So, A>B

So  we will subtract 15.75 from 176.3.

176.30 -15.75=

176.30     ----A

- 1 5.75     ----B

Hundreths place of A - Hundreths place of B =  0-5=10-5=5

Tenth place of A  - Tenth place of B =12-7=5

ones place of A - ones place of B=5-5=0

Tens place of A - Tens place of B =7-1=6

Leave 1 as it is.

So the solution is 160.55

Now coming back to the Explanation by four friends of Mina

Ivy’s explanation: I lined up the numbers to subtract. [As i have explained above you have to find first which number is bigger , then first you must write bigger number then if the bigger number has  only tenth place value mark hundred place as 0 and then start subtracting from Right to left.]

Hannah’s explanation: I lined up the two decimals according to place value. I put a 0 in the hundredths place to make it easier for me to subtract.   [ As i said above first you have to choose which number is bigger then you can proceed as you have done.]

Jose’s explanation: I lined up the two decimals according to place value   [ Jose you have made same mistake, first find which number is bigger then line up the number according to their place value, write the bigger number first then start subtracting as i have explained above.]

An’s explanation: I counted up from 15.75 to 176.3 to find the difference. I underlined each number I added on each line.   [ Too lengthy and very time consuming. Use the method as i have explined above.]