Addition and Subtraction Practice

Solve:   $-16+24$  

Answer explanation

MC Santi says: "Different signs: SUBTRACT!"  And give the answer the sign of the "bigger" number, which in this case is the 24.

Another way to think of this is that "the positive team wins by 8".

Tags

CCSS.7.NS.A.1C

Solve:   $14-22$  

Answer explanation

Try rewriting this subtraction problem in its addition form using "keep, change, switch".  Then apply the addition rules.

Tags

CCSS.7.NS.A.1C

Solve:  $-12+-15$  

Answer explanation

MC Santi says: "Same signs: ADD" and give the answer the same sign as the numbers.

Tags

CCSS.7.NS.A.1C

Solve:   $4-\left(-9\right)$  

Answer explanation

Try rewriting this in its addition form, using "keep, change, switch".  You'll be glad you did!

Tags

CCSS.7.NS.A.1C

Solve:   $4\frac{1}{2}+-8\frac{1}{8}$  

Hint:  How would you solve this if it were just whole numbers (4 + -8)?

Answer explanation

Whenever you are adding or subtracting fractions, make sure to rewrite them with a common denominator, and remember to adjust the numerator, too (whatever you do to the bottom, you do to the top).

Tags

CCSS.7.NS.A.1C

Solve:   $-10-25$  

Answer explanation

Try rewriting this in its addition form using "keep, change, switch".  You could also consider modeling this using a number line.

Tags

CCSS.7.NS.A.1C

The altitude at the top of Blueberry Hill is 254 feet above sea level. In neighboring Tangerine Gully, the altitude is 36 feet below sea level (you can think of this as -36 feet).

What is the difference in altitude from the bottom of Tangerine Gully to the top of Blueberry Hill?

(You may find it helpful to sketch a number line in your math notebook or on a piece of paper.)

Answer explanation

Did you sketch this out on a number line? Consider using a vertical number line (one that looks almost like a thermometer).

Was your answer marked incorrect because you left off the label? If so, make a mental note to label your answers for word problems, and move on to the next question.

Tags

CCSS.7.NS.A.1C

Solve:   $-15-\left(-8\right)$  

Answer explanation

Rewrite as an addition problem using "keep, change, switch".  If you have missed this and any earlier subtraction problems, and you still aren't doing "keep, change, switch", then I would recommend starting to do so!

Tags

CCSS.7.NS.A.1C

Solve:   $-93+67$  

Answer explanation

Make sure you are following the rules on your orange sheet.  You might try sketching a quick number line to help you visualize this, especially if you are missing lots of these problems.

Here's another way of looking at it:   Which team wins?  by how much?

Tags

CCSS.7.NS.A.1C

In the morning, the temperature was -13 degrees Celsius. By 1:00 PM, the temperature was 38 degrees higher.

What was the temperature at 1:00 PM?

Answer explanation

If your answer was marked incorrect because of labelling or formatting, make a note of it and move on to the next question.

If you got something other than 25, try drawing a number line to represent this situation.

Tags

CCSS.7.NS.A.1C