Subtraction 4 Mental Strategies

Subtraction 4 Mental Strategies

Partitioning

Round and Adjust

​Counting On

​Counting

​Correcting HW

​Please Open Your copybooks

​Correcting HW

​Please Open Your copybooks

​Subtraction Keywords

​How many more than

​How many less than

What's the difference

​How many fewer

How many less than

​Take away

​https://www.youtube.com/watch?v=3KHa16KZeHU

Multiple Choice

What is a difference?

• The answer to any math problem.

• The answer to a subtraction problem.

• The answer to an addition problem.

​Mental Subtraction

When we subtract numbers mentally, we are trying to find a quick way of subtracting the numbers in our heads. Let us take a look at some examples.

Fill in the Blanks

What is 569 - 53?

​49-34 = 15

Fill in the Blanks

Miles was walking 56 dogs. 19 dog ran away. How many dogs are left?

​87 - 75 =

Fill in the Blanks

Subtract 4 from 802 mentally.

Fill in the Blanks

706 - 15

Write the 1) strategy name Then 2) answer the following subtraction problems:-

​(Round & Adjust , Counting on , Counting back , Partitioning)

Homework - Solve in your copybook

​Answers

Please Write the final answers From your copybooks in the next slides

Fill in the Blanks

$\left(1\right)456\ -\ 321$

Fill in the Blanks

$\left(2\right)456\ -\ 298$  

Fill in the Blanks

$\left(3\right)508\ -\ 489$  

Fill in the Blanks

$\left(4\right)406\ -\ 12$