Adding
Subtracting
Multiplying
Rules
100

5.7 + 3.8

9.5


100

3.6 - 1.9

1.7

100

*Use front end estimation*

8.7 x 3.4

27

100

What are three examples of decimals in real life?

Ex: Money/ price, Taxes, Measurements, time, speed, etc.

200

17.4 + 7.3

24.7

200

7.54 - 4.88

2.66

200

5.64 x 8

45.12

200

When writing down a subtracting or adding question what do you need to do before you start solving?

Line up the decimals

300

23.34 + 76.99

100.33

300

23.78 - 14.79

8.99

300

13.12 x 4

52.48

300

After multiplying what do you have to put back in to get your final answer? 

The decimal

400

138.25 + 562.94

701.19

400

439.12 - 76.29

362.83

400

123.45 x 32

3950.40

400

Which math skill requires placeholder zeros?

Subtracting


500

45.67 + 77.312

122. 982

500

723.34 - 184.935

538.405

500

97.45 x 9.7 

945.265

500

Using what you know about multiplication what do you think the first step in division is?

Remove the decimal