Unit 2 Study Guide Name ______

I.  Know these vocabulary words.

Landmark – object or feature that stands out

Maximum – largest number in a data set

Minimum – smallest number in a data set

Range – the difference between the maximum and minimum (subtract maximum minus minimum)

Mode – the most frequent number in a set of data

Median – the middle number in an organized set of data

II.  Practice mental math.

=>Knowing your basic facts can help you add and subtract numbers mentally.

Example: 5 + 7 = 12

50 + 70 = ??

Think: If 5 ones + 7 ones = 12 ones

Then 5 tens + 7 tens = 12 tens (which equals 120)

And 500 + 700 = 1,200

Because 5 hundreds + 7 hundreds = 12 hundreds (or 1200)

Example 2: 16-8 = 8

160 – 80 = ??

Think: If 16 ones – 8 ones is 8 ones,

Then 16 tens – 8 tens is 8 tens (or 80)

And 1600 – 800 = 800

Because 16 hundreds – 8 hundreds = 8 hundreds (of 800)

This is adding and subtracting extended facts.

Solve these problems mentally.

1. 4 + 9 = _____ 2. 40 + 90 = ______3. 400 + 900 = _____

4. 15 – 7 = _____ 5. 150 – 70 = ______6. 1,500 – 700 = _____

=> Once you’re comfortable with adding and subtracting extended facts, you can add and subtract numbers like these:

53 + 30 = _____ (You know what 50 + 30 equals, now just add 3 more!)

87 + 70 = _____ (You know what 80 + 70 equals, now just add 7 more!)

90 – 34 = _____ ( You know what 90 – 30 equals, now just subtract 4 more!)

Try it:

1. 42 + 50 = _____ 2. 25 + 60 = ______3. 76 – 40 = _____

III.  Be able to state the value of a given digit.

Know your place-value chart. Be sure to use commas to separate the “Periods.”

------Millions------Thousands------Units------

hundred millions / ten millions / millions / hundred thousands / ten thousands / thousands / hundreds / tens / ones

Example: What is the value of the given digits in this number? 5,062

The 5 is worth 5000.

The 0 is worth 0.

The 6 is worth 60

The 2 is worth 2.

Try it.

43,720,195 7,856,210

The 3 is worth ______. The 7 is worth ______.

The 7 is worth ______. The 8 is worth ______.

The 0 is worth ______. The 6 is worth ______.

The 1 is worth ______. The 1 is worth ______.

IV.  Be able to add and subtract 3- and 4-digit numbers.

You may use the algorithm that works best for you (traditional or partial-sums).

43 719 4,392 12,033

+17 - 497 + 137 - 6,025

V.  Be able to display and describe data.

Interpret a tally chart and find the maximum, minimum, range, mode, and median for a set of data. Construct a bar graph or a line plot.

A class collected data on the number of pets in their households. Use the tally chart to answer the following questions.

Number of Pets / Number of Households
0
1
2
3
4
5
6
7
8

a.  How many households have 2 pets? ______

b.  What is the maximum number of pets? ______

c.  What is the range of the number of pets? ______

d.  What is the mode (most frequent number) of pets? ______

e.  What is the median of pets? ______

Explain how you found the median.

______

f.  Make a bar graph of the data. Pets per Household

0 1 2 3 4 5 6 7 8

g.  Make a line plot of the same data.

0 1 2 3 4 5 6 7 8

Number of Pets

VI.  Also, review your polygons!

Be sure you can draw a polygon with a least one right angle. Mark the right angle(s) with the square corner symbol. Be able to identify your polygon in all the ways that you can.

For example, if I draw a rectangle…a rectangle is also a parallelogram, which is a quadrangle, which is a polygon.