TextBook Page 61. Question #16

Bella is more comfortable working with integers that with positive and negative decimal numbers. This is her way of understanding -4.3 + 2.5.

-4.3 is -43/10 or -43 tenths.

2.5 is 25/10 or 25 tenths.

-43 tenths + 25 tenths is -18 tenths.

So. -4.3 + 2.5 = -1.8.

a) Use Bella's method to determine 6.1 + (-3.9).

6.1 is 61/10 or 61 tenths

-3.9 is -39/10 or -39 tenths

61 tenths + -39 tenths is 22 tenths

22 tenths is 22/10 or 2.2

So. 6.1 + (-3.9)= 2.2

b) How could you modify Bella's method to determine 
    1.25 - 3.46 ?

1.25 is 125/100 or 125 hundredths 

3.46 is 346/100 or 346 hundredths

125 hundredths - 346 hundredths is -221

So. 1.25 - 3.46 = -221