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Cogito

Grade 1 Math · Chapter 8 · Lesson 8

Practice Worksheet

Adding Two-Digit Numbers

Add tens to tens, then ones to ones.

10 problems · about 13 minutes · 1.NBT.C.4

NameDate

Figure — use these to answer the problems

Count the rods from both rows, then count the cubes.
First number
and Second number
Altogether

Tens

3

Ones

7

13 + 24 = 37

First number13
Second number24
Figure 1

Warm-Up Review

From earlier lessons. Loosen up before the new work.

4 problems

  1. From “Word Problems Within 40”

    Whole 35, one part 15. Other part?

    Answer

  2. From “Tape Diagrams for Stories”

    Parts of 13 and 12. What is the whole?

    Answer

  3. From “Making the Next Ten”

    29 + 5 = ?

    Answer

  4. From “Adding Ones Without Making a New Ten”

    31 + 6 = ?

    Answer

Warm Up

Straightforward practice. Get the method working first.

3 problems

  1. 21 + 14 = ?

    Answer

  2. What do you add first?

    • Tens with tens.
    • Tens with ones.

  3. 11 + 12 = ?

    Answer

Build It Up

The same ideas with more to keep track of.

1 problem

  1. 14 + 23 = ?

    Answer

Stretch Yourself

Mixed problems. Work out what kind of question it is before you start.

2 problems

  1. 22 + 16 = ?

    Answer

  2. Two Classes

    12 children in one class and 15 in another. How many?

    Answerchildren