marvy math strategies

Tricks & Shortcuts to Adding & Subtracting Basic Facts

By Vicki Dabrowka ~ Eagle Cove School

www.eaglecoveschool.org

Marvy Math

Strategies

http://www.eaglecoveschool.org/

Zero Facts

Could it get any easier??Zero is a mirror.

Anything plus or minus 0 is itself!

Zero Facts

327 + 0 = ___

0 + 2,748 = ______

42,892 – 0 = _______

5,000,000 – 5,000,000 = _

Zero Facts

327 + 0 = 327

0 + 2,748 = 2,748

42,892 – 0 = 42,892

5,000,000 – 5,000,000 = 0

Count Ons

Anything +1, +2, +3, +4

Count Ons

7 + 4 = ____

Anything +1, +2, +3, +4

Count Ons

7 + 4 = Think “7,” Then count on: 8, 9, 10,

11

49 + 3 = __

Anything +1, +2, +3, +4

Count Ons

49 + 3 = 52

128 + 4 = ___

Anything +1, +2, +3, +4

Count Ons

128 + 4 = 132

Remember:Anything +1, +2, +3,

+4

Count Backs

Anything -1, -2, -3, -4

Count Backs

13 – 4 = _____

Anything -1, -2, -3, -4

Count Backs

13 – 4 = Think “13”Then count on: 12, 11, 10,

9

15 – 3 = ____

Anything -1, -2, -3, -4

Count Backs

15 – 3 = 12

31 – 2 = ____

Anything -1, -2, -3, -4

Count Backs

31 – 2 = 29

383 – 4 = ____

Anything -1, -2, -3, -4

Count Backs

383 – 4 = 379

Remember:Anything -1, -2, -3, -4

Count Ups

11 - 8

“Count Ups” are 2 numbers in subtract that are pretty close

together… it’s kind of the opposite of a Count Back &

the answer is usually 1, 2, 3, 4.

Count Ups

11 - 8

Start with the littlest number & COUNT UP to the larger one

(clapping tends to help!)

Count Ups

11 – 8 = __ 8…….9, 10, 11 You

counted up 3 times!

Remember: Start with the littler number & COUNT UP to the larger one. (Did you clap

or tap the desk too? It really helps!)

Count Ups

11 – 8 = 3 8…….9, 10, 11 You

counted up 3 times!

It’s true!Now try a few!

Count Ups

15 – 11 = __

Start with the littler one & COUNT UP

to the larger one.

Count Ups

15 – 11 = 4

11…12, 13, 14, 15

You counted up 4 times.

Count Ups

51 – 47 = __

Start with the littler number & COUNT UP

to the larger one.

Count Ups

51 – 47 = 4

47….48, 49, 50, 51You counted up 4 times.

It works for any 2 numbers that are close together!

10 Frame

Knowing your Facts of 10 or thinking of the 10 Frame picture

helps a ton! It’s like a short egg carton with exactly 10

spots.

10 Frame

We all know that 5 + 5 = 10 and 10 – 5 = 5…

use that information to help you visualize a 10 frame & fill the

frame!

10 Frame

__ + __ = 10

10 - __ = __

Lock in some mental pictures of things that naturally come in doubles. Then, think of these

double pictures to help you with your math facts!

Doubles

1 + 1 = _

Eyes

1 + 1 = _

2 Eyes

1 + 1 = 2

2 + 2 = _

2 + 2 = _

__ Wheels

2 + 2 = 4

4 Wheels

3 + 3 = _

3 + 3 = _

__ Clover leaves

3 + 3 = 6

6 Clover leaves

4 + 4 = _

4 + 4 = _

__ spider legs

4 + 4 = 8

8 spider legs

5 + 5 = _

5 + 5 =

__ fingers on 2 hands

5 + 5 = 10

10 fingers on 2 hands

6 + 6 = _

6 + 6 = __

__ eggs in a dozen

6 + 6 = 12

12 eggs in a dozen

7 + 7 = __

7 + 7 = __

__ days in 2 weeks on the calendar

7 + 7 = 14

14 days in 2 weeks on the calendar

8 + 8 = __

8 + 8 = __

__ tentacles on 2 octopus

8 + 8 = 16

16 tentacles on 2 octopus

9 + 9 = __

9 + 9 = __

__ Wheels on an 18-wheel semi truck

9 + 9 = 18

18 Wheels on an 18-wheel semi truck

Doubles for Subtract

Think of your Add Double pictures in

reverse! You’ve got to love

Fact Families!

Once you know your Doubles, this will be a

great strategy for you!!

It works for all of them! Here are just 2

examples.

Doubles + 1

Think of your double facts,

then add one more!

Doubles + 1

6 + 7 = ____

Think of your double facts, then add one more!

Doubles + 1

6 + 7 = ____

Think of your egg carton dozen, then add 1 more egg!

Doubles + 1

6 + 7 = 13 eggs

+

Think of your double facts, then add one more!

Doubles + 1

8 + 7 = ____

Think of your 2 weeks of 7 days,

then add 1 more day!

Doubles + 1

8 + 7 = 15 days

Think of your 2 weeks of 7 days, then add 1 more day!

Doubles + 1

Challenge yourself to make up some of your

own!Go for some tricky

ones!!

Doubles + 1

Easy 9’s for Add

This works for any

1-digit number plus the number 9.

Easy 9’s for Add

8 8 8+ 9 + 9 + 9 1 17

Put down a “1” to make a teenage numbers…Think of 1 less than the other

digit.

Easy 9’s for Add

6 4 7+ 9 + 9 + 9

Now you try a few.

Easy 9’s for Add

6 4 7+ 9 + 9 + 9

1 __ 1 __ 1 __

Put down the 1’s to make teenage numbers.

Easy 9’s for Add

6 4 7+ 9 + 9 + 9

1 __ 1 __ 1 __

Think 1 less than the other number. (Remember this

only works for 9’s.)

Easy 9’s for Add

6 4 7+ 9 + 9 + 9

15 1 __ 1 __



Easy 9’s for Add

6 4 7+ 9 + 9 + 9

15 13 1 __



Easy 9’s for Add

6 4 7+ 9 + 9 + 9

15 13 16



Easy 9’s Subtract

Just like there’s an Easy 9 Addition,

there’s Easy 9 Subtract!

Easy 9’s Subtract

1 6 1 4 1 7 - 9 - 9 - 9

This works for any “teenage” number minus

9.

Easy 9’s Subtract

1 6 1 4 1 7 - 9 - 9 - 9

Put a tiny plus sign in between the two digits of

your teenage number.

Easy 9’s Subtract

1+6 1 4 1 7 - 9 - 9 - 9



Easy 9’s Subtract

1+6 1+4 1 7 - 9 - 9 - 9



Easy 9’s Subtract

1+6 1+4 1+7 - 9 - 9 - 9



Easy 9’s Subtract

1+6 1+4 1+7 - 9 - 9 - 9

Add the two digits together—Voila! You’ve got your difference

—Remember, it only works for “-9”

Easy 9’s Subtract

1+6 1+4 1+7 - 9 - 9 - 9

7 Add the two digits together—

Voila! You’ve got your difference—

Remember, it only works for “-9”

Easy 9’s Subtract

1+6 1+4 1+7 - 9 - 9 - 9

7 5Add the two digits together—



Easy 9’s Subtract

1+6 1+4 1+7 - 9 - 9 - 9

7 5 8Add the two digits together—



Add Leftovers

If you know all of your addition strategies and use them…there

are only 3 leftover problems: Memorize them!

5 + 7 = 12 5 + 8 = 136 + 8 = 14

Add Leftovers

5 + 8 = __

Add Leftovers

5 + 8 = 13

Add Leftovers

8 + 6 = __

Add Leftovers

8 + 6 = 14

Add Leftovers

5 + 7 = __

Add Leftovers

5 + 7 = 12

Add Leftovers

Don’t forget about the turn arounds too!7 + 5 = __

8 + 5 = __6 + 8 = __

Add Leftovers

Don’t forget about the turn arounds too!7 + 5 = 12

8 + 5 = __6 + 8 = __

Add Leftovers


8 + 5 = 136 + 8 = __

Add Leftovers


8 + 5 = 136 + 8 = 14

10-Finger Subtract

When you’ve used all of your other subtract strategies, 10-Finger Subtract will come to

your rescue!

10-Finger Subtract

Imagine your right hand pointer fingernail as a

big ZERO!

10-Finger Subtract

Use your ZERO pointer-finger to turn a problem into a 10-frame & an easier 10’s fact so you can

solve a simpler problem 1st to help you solve a harder problem!

10-Finger Subtract

1 6- 7

Move your ZERO pointer finger to cover your math fact in order

turn your problem into a 10-frame, easier 10’s fact.

10-Finger Subtract

1 6- 7

Move your ZERO pointer finger to turn a

problem into a 10-frame 10’s fact.

10-Finger Subtract

1 6- 7

Now you have a new temporary problem:

10 – 7

10-Finger Subtract

1 6- 7

All of a sudden, it’s a way easier problem!

10 – 7 = 3

10-Finger Subtract

1 6- 7

Lock in the 3 from 10 minus 7 into your

brain…but wait! That’s not the answer!

10-Finger Subtract

1 6- 7

3 is still in your brain.Now lift your finger and

PEEK! What do you see?

10-Finger Subtract

1 6- 7

3 is still in your brain.When you peek you see a 6.

Now think “6 + 3 (still in your brain)

= ?? ”

10-Finger Subtract

1 6- 7

6 + 3 = 9

So….16 – 7 = 9

10-Finger Subtract

1 4- 8

Okay! You are ready to try a few more!

10-Finger Subtract

1 4- 8

14 – 8 becomes 10 – 8.10 – 8 = ??

10-Finger Subtract

1 4- 8

10 – 8 = 2 Lock in the 2!Now PEEK!

10-Finger Subtract

1 4- 8

You see 4! 4 + 2 = ??

10-Finger Subtract

1 4- 8

4 + 2 = 6

So………14 – 8 = 6!

10-Finger Subtract

1 1- 5

You do it!

10-Finger Subtract

1 1- 5

Think 10 – 5.Lock in the answer

in your brain.

10-Finger Subtract

1 1- 5

Now PEEK!1 + your brain number = ??

10-Finger Subtract

1 1- 5

Now PEEK!1 + your brain number = ??

11 – 5 = ??

Knowing Your Math Facts

are the Key to Future

Success in Math!

What are you going to do to lock and load

your math facts??

Go Forth, young

mathematician, and

memorize those basic math facts!

THE END!

Or is it the BEGINNING

of your success???

marvy math strategies

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