Pre-Algebra

Lesson 2.11, 2.12

Subtracting Decimals, Part 1 & 2

By stating the objectives for the lesson, retention increases by 24%!

Did you know that...

Rules:

Same sign (+ +, - -)

add numbers together, keep sign

Different signs (+ - , - +)

find difference, take sign of higher number

Review of Adding Decimals:

Review of Adding Decimals:

Review of last week:

What is subtraction?

=

=

You can turn any subtraction problem into an addition problem:

6 - 4

-9 - 13

8 - -3

-14 - (-5)

1.# - #

2. - # - #

3. # - (-#)

4. -# - (-#)

Trust Fall

https://www.youtube.com/watch?v=wPOgvzVOQig

1) - 43.4 + x = 15.34 2) x + 19.2 = -19.9

3) x - 98.3 = -12.3 4) x + 55.33 = 23.2