Why is 57 ones same as 5 tens and 7 ones

Answer 1

The decimal number system is a positional number system. Each position has a place value.

Moving from the decimal point going left, there is:

ones place -- with a value of 7

tens place -- with a value of 5

That is, 5 tens and 7 ones, or 5*10 + 7*1 = 50+7 = 57

Now, notice that decimal values to the right of a decimal point also have place value. From the decimal point moving right:

1. theths place
2. hundredths place

The 5's in the number 555.55 all have different values because they occupy different places.

Answer 2

Think of 5 tens as 5 x 10 = 50

Think of 7 ones as 7 x 1 = 7

Now add 50 + 7 = 57