# math mental math help

posted by
**marko** on
.

i need to use mental math and the distributive property to simplify:

can you pls check if this correct?

a) 19(-6) i got: -114

or do i do like this:

10*(-6)=-60

9*(-6) =-54

-60 + -54= -114

b) 102* $21 i got: $2142

or do i do mental math like this:

100*21 = 2100

2 * 21 = 42

2100 + 42 = $2142

c) 26*97 i got: 2522

or do i do mental math like this:

20 * 97 = 1940

6* 97 = 582

1940 + 582 = 2522

d) 9 * $4.98 i got: $44.82

or do i do mental math like this:

9 * $4.00 = $36.00

9*.98 = 8.82

36.00 + 8.82 = $44.82