1.NBT.4: Adding Within 100

1. Base Ten Blocks

Use ten-rods and unit cubes. For 25 + 3, show 2 ten-rods and 5 units, then add 3 more units to get 2 ten-rods and 8 units (28).

2. Number Line Jumps

Draw a number line. For 34 + 20, start at 34 and make two jumps of 10 to land on 54.

3. Hundred Chart

Use a 1-100 chart. For adding 10, move down one row. For adding 1, move right one space.

4. Place Value Mat

Draw a mat with "Tens" and "Ones" columns. Show each number, then combine the columns to find the sum.

1. Shopping Math

At the store: "We have 23 apples and need 5 more. How many will we have?" Use real objects when possible.

2. Toy Collections

Count toys: "You have 15 cars and got 10 more for your birthday. How many cars do you have now?"

3. Sticker Charts

Use sticker reward charts: "You had 27 stickers and earned 6 more today. How many stickers total?"

4. Cooking Together

Measure ingredients: "We need 35 chocolate chips and 20 more. How many is that altogether?"

5. Game Scores

Keep score in games: "You had 42 points and just scored 8 more. What's your new total?"

1. Start with Multiples of 10

Begin with easier problems like 23 + 10 or 45 + 20. These build confidence and understanding.

2. Use the "Add Tens First" Strategy

For 34 + 25, think: "30 + 20 = 50, then 4 + 5 = 9, so 50 + 9 = 59."

3. Break Apart Numbers

For 27 + 8, think: "27 + 3 = 30, then 30 + 5 = 35" (breaking 8 into 3 + 5).

4. Use What They Know

Connect to facts they know: "You know 7 + 3 = 10, so 27 + 3 = 30."

5. Make it Concrete

Always use objects or drawings until the mental strategies become natural.

Activity 1: Add 10 Game

Call out numbers and have your child add 10: "25 plus 10 equals..." This builds mental math skills.

Activity 2: Two-Step Addition

For 36 + 7, say: "First add to the next ten: 36 + 4 = 40. Then add the rest: 40 + 3 = 43."

Activity 3: Story Problems

Create simple stories: "There were 28 birds in a tree. 6 more birds came. How many birds now?"

Activity 4: Number Line Hops

Draw a number line and practice "hopping" by tens and ones to solve addition problems.

By the middle of the year, your child should:

• Add 10 to any two-digit number mentally (23 + 10 = 33)
• Add single digits to two-digit numbers using objects or drawings
• Understand that adding doesn't change the tens place when adding small numbers

By the end of the year, your child should:

• Add two-digit numbers and multiples of 10 mentally (34 + 20 = 54)
• Add two-digit and one-digit numbers with and without regrouping
• Use multiple strategies (objects, drawings, mental math) to solve problems
• Explain their thinking when solving addition problems

Simple Assessment:

Give your child problems like 25 + 4 and 37 + 20. Watch their strategy and ask them to explain.
Ask: "How would you solve 28 + 6?" Look for logical thinking and place value understanding.
Present a story problem: "You have 35 stickers and get 8 more. How many do you have now?"