The ideas in this decimals lesson are taken from Math Mammoth Decimals 1 book ($4.00 download). Only a few examples of each problem type are shown.

Review

1.  Draw pictures to represent the decimals, and write the decimals as fractions too.

 2.  Make a number line from 

a) From 3.4 till 5.6, tick marks at every tenth.

b)  From 0.38 till 0.54, with tick marks at every hundredth.

3.  Fill in!  In the first one, find what was subtracted.  In the second one,  Figure out what was done in each step - either addition or subtraction!

4.  Continue the patterns.

5.  Multiply in columns.  Estimate first!

6.  Find the missing factor.

7.  Add or subtract in columns. Estimate first!

8.  Add mentally.  Pay close attention to the number that only has tenths.  Before adding, tag a zero to it so the addends will have the same amount of decimals.  Write the problems using fractions also.

 
9.  Compare and write <, >, or = .

a. 0.23   0.2    e. 0.35   0.39    i. 6.5     6 1 2

b. 1 2   0.7   f. 5.6   5.45   j. 7.8     8.7

d. 1.38   1.8   h. 14 10     1.3   l. 0.8     0.18

10.  Write the following decimals in order from smallest to greatest:
  5.6   5.06   5.56   5.62   6.5   5.0  5.16

11.  Word problems.

b.  Dad pays with $10.  What is his change?

e.  Which is cheaper: to buy 20 ice cream cones for for $0.89 apiece, or to buy two big boxes of ice cream (enough for 20 people) for $7.95 apiece?

f.  Find the actual true prices for some standard ice cream cone, and a box of ice cream, and do the comparison again.

g.  The earth goes around the sun one time in 365.24 days.  This is called the solar year.  It is also 365 days, 5 hours, and 48 minutes.  

Use the decimal 365.24 days per year.  How many days are in two solar years?  

 In four solar years?

In how many solar years does the 0.24 days over 365 days make a need for an extra day within the year?

Do you know when that day is, and how is the year with the extra day called? 

h.  The time between two new moons is 29.531 days.  This time period is called lunar month.  How many days is 12 lunar months?

i.  Mars goes once around the Sun in 686.95 of our days. Mercury does the same trip in 87.96 days.  How many days quicker is Mercury?
Why is Mercury quicker?

Calculate how many years are in 6 Mercury years, 7 Mercury years, and 8 Mercury years.  Based on that, choose the right alternatives:

The ideas in this decimals lesson are taken from Math Mammoth Decimals 1 book ($4.00 download). Only a few examples of each problem type are shown.