Curated OER
Mental Math: Adding 10s
To develop mental math skills for adding 10s, learners read an example, solve one carefully scaffolded problem, and then complete 6 more independently. Pictures of 10-rods make the connection between sets of 10 and the corresponding...
Maths Blog
Adding/Subtracting Whole Numbers in Your Head
Exercise those mental math muscles! This worksheet contains 10 addition and 10 subtraction problems which require learners to compute sums or differences in their heads. A quick review at the top of the page provides a strategy based on...
Savvas Learning
How Many Hundreds?
Mental math skills are really important to develop. Kids practice metal computation by first adding the hundreds then the tens and ones. There are nine addition and nine subtraction problems to solve. This attractive worksheet is...
Curated OER
Adding in Our Heads
A good presentation on adding two-digit numbers. Learners are shown how to partition the numbers before trying to add them in their heads. A frog is the featured teacher of the PowerPoint, and he leads viewers through many problems and...
Curated OER
Mentally Add Larger Numbers
Using what they know about adding 10s and 100s, learners attempt to mentally solve 18 addition problems. Each problem requires them to think of the nearest 10 or 100, add them together, then add the remaining units.
Curated OER
Mental Math: Add Tens Practice 10.1
In this adding tens worksheet, students solve 11 problems in which tens are added. Students may use a basic fact to help. Example: 2 tens + 1 ten.
Primary Junction
Adding Tens
Build on your learners' confidence in quick addition as they discover strategies to add tens to two-digit numbers. After reviewing counting by 10's, they discuss tactics to add multiples of 10 to other numbers. They visualize how to...
Scholastic
Look for Easy Numbers for E-Z Addition
All kids learn differently. For some, mental math is the best and most efficient way to add a series of numbers. After viewing a few sample problems, learners find ways to add numbers to 10 before adding them all together, and then write...
Curated OER
Mentally Add Two 2-Digit Numbers pg. 1
Mental math addition is the focus of this activity. Students apply a strategy outlined in the activity to find the sums. In this activity, students find the answers for twenty problems. Answers appear at the end.
Curated OER
10 More or 10 Less?
Take a rocket to the stars with using a math instructional activity. Here, four sets of alien saucers, moons, rockets, and stars prompt young learners to match numbers with one more or ten more. Color the pictures for extra fun when...
Curated OER
Addition Practice #1
Show young mathematicians that they are fully capable of mentally adding two-digit numbers. They start by solving 12 two-addend problems (all with two-digit numbers and aligned horizontally). There is no room to show work. Consider...
Curated OER
Mental Math Strategies
In this mental math worksheet, students study the detailed instructions and examples for adding or subtracting numbers using "breaking apart" or compensation. Students solve 17 mental math problems.
Curated OER
Horizontal Addition
Here are four examples of double-digit horizontal addition. Learners are shown how to compute numbers horizontally, by first adding the tens and then the ones columns and then adding them both together. This is a great way to boost...
Curated OER
Addition-Adding on Tens, Sheet 1
In this adding on tens worksheet, students add multiples of 10 to given numbers. A reference web site is given for additional activities.
Curated OER
Roll Seven!
Roll Seven is a fun and engaging dice game that encourages the use of mental math.
Curated OER
10 More or 10 Less
Practice adding and subtracting 10 with this outer space worksheet. On the top, scholars match digits floating in stars with sums inside a spaceship. Next, they do the same with subtracting 10, connecting numbers to differences. These...
Curated OER
The Part-adder 1
Second graders investigate the addition of whole numbers. They mentally perform calculations involving addition and subtraction. They make sensible estimates and check the reasonableness of answers.
Curated OER
Addition: Two Digit Mental Addition
In this 2-digit addition activity, learners learn how to solve 2-digit math problems in their heads instead of on paper. They then solve the 20 problems on the activity. The answers are on the last page.
Curated OER
The Numbers Get Larger
Second graders examine how to use mental strategies for addition and subtraction. They look at part/whole strategies for multi-digit problems and define which one would be best used for a particular problem. They use tens frames to solve...
Curated OER
Compatible Numbers To Ten
Students solve both addition and subtraction facts and discover the relationship between adding and subtracting equations. Students read real life word problems, extrapolate needed information, and write equations to solve the story...
Curated OER
Estimation and Computation
Second graders practice their estimation skills using blocks. In this math lesson, 2nd graders explain how estimating makes addition easier. They complete a worksheet after the lesson to reinforce new learning.
Curated OER
Addition: Double digit
In this double-digit addition worksheet, learners solve 30 addition problems. Both addends in each problem are two-digit numbers.
Curated OER
Big Steps
Second graders practice developing strategies for mental calculation when counting in 10s and 100s. They mentally perform calculations involving addition and subtraction to be able to state the difference between numbers by counting in...
Curated OER
Addition Strategies: Compensation
In this math worksheet, students learn the addition strategy of compensation: adding an easy number like 10, 20 or 30 and then subtracting a very small number like 1 or 2. Students solve 12 problems on the page.