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Lesson plan Grade 1 Math

Bramble Hill's Leaf Bags: A Grade 1 Adding Tens Lesson

A 45-minute grade 1 lesson where students add tens and ones with bundled cubes to total the leaf bags cleared from a school's storm drains.

Objectives

  1. Students will add a multiple of ten to a two-digit number using bundles of ten.
  2. Students will add a one-digit number to a two-digit number and regroup when ten ones appear.
  3. Students will draw tens as sticks and ones as dots to show a sum.

Vocabulary

Storm drain
A storm drain is the grate at the edge of a street that swallows rainwater and sends it through pipes to the nearest creek or river. That water is usually not treated, so only rain belongs down the drain.

Also: tens, ones, bundle, sum

Teacher overview

Bramble Hill School is a made-up school at the bottom of a wooded slope, where fallen leaves pile against the curb every autumn and block the storm drains until rainwater backs up across the parking lot. The custodian and the first-grade class fill paper leaf bags over several days and keep a running count of how many bags the crew has hauled away. That running count is the reason to add tens to a two-digit number in this lesson. The misconception the lesson targets is the habit of adding a multiple of ten by changing the ones digit as well, so that a student turns 24 plus 30 into 57 without noticing that the leftover ones never moved. Bundling real cubes keeps the four leftover ones visibly untouched while three new bundles arrive.

Procedure

Hook (5 min): Show a photo or a sketch of leaves packed against a curb grate and say that the crew filled 24 bags on Monday. Pour out 24 loose cubes. Ask how long it would take to count all the bags one at a time if the crew filled twenty more, and take a few guesses without correcting them.

Direct instruction (10 min): Bundle the 24 cubes into two bundles of ten and four loose ones, placing them on the place-value mat. Add two more finished bundles to the tens column and say aloud: "Two tens plus two tens is four tens, and the four ones did not change, so 24 plus 20 is 44." Repeat with 24 plus 5 so students see the ones column change while the tens stay put.

Guided practice (15 min): Pairs work questions 1 through 3 on the handout with cubes and a mat. One partner builds the starting count and the other adds the new bags, then they trade roles. Circulate and ask pairs to point at the column that changed and the column that did not.

Independent practice (10 min): Students work questions 4 through 6 by drawing tens as sticks and ones as dots instead of building with cubes. Cubes stay on the table for any student who needs to check a drawing.

Closure / exit ticket (5 min): Students answer question 7 on an index card and hand it in on the way out. Sort the cards into correct and incorrect piles before the next math block; if more than five students changed the ones digit while adding tens, reteach with bundles the following day.

Bramble Hill's Leaf Bags: A Grade 1 Adding Tens Lesson — Grade 1 Math
Name: ____________________________ Date: ______________

Student Handout

Draw tens as sticks. Draw ones as dots. Then write the total.

  1. The crew filled 24 leaf bags. Then they filled 10 more bags. How many bags in all?
  2. The crew filled 24 leaf bags. Then they filled 30 more bags. How many bags in all?
  3. The crew filled 42 leaf bags. Then they filled 5 more bags. How many bags in all?
  4. The crew filled 36 leaf bags. Then they filled 20 more bags. How many bags in all?
  5. The crew filled 58 leaf bags. Then they filled 7 more bags. How many bags in all?
  6. The crew filled 45 leaf bags. Then they filled 40 more bags. How many bags in all?
  7. The crew filled 63 leaf bags. Then they filled 30 more bags. How many bags in all?

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key
  1. Answer: 34 bags. 24 is 2 tens and 4 ones. One more ten makes 3 tens and 4 ones, which is 34.
  2. Answer: 54 bags. 24 is 2 tens and 4 ones. Three more tens makes 5 tens and 4 ones, which comes to 54. The 4 ones never change.
  3. Answer: 47 bags. 42 is 4 tens and 2 ones. Adding 5 ones gives 4 tens and 7 ones, which comes to 47.
  4. Answer: 56 bags. 36 is 3 tens and 6 ones. Two more tens makes 5 tens and 6 ones, which comes to 56.
  5. Answer: 65 bags. 58 is 5 tens and 8 ones. Adding 7 ones gives 15 ones, so ten of them bundle into a new ten. That leaves 6 tens and 5 ones, or 65.
  6. Answer: 85 bags. 45 is 4 tens and 5 ones. Four more tens makes 8 tens and 5 ones, which comes to 85.
  7. Answer: 93 bags. 63 is 6 tens and 3 ones. Three more tens makes 9 tens and 3 ones, which comes to 93.

Differentiation

Support

Pre-bundle the tens so these students only place finished bundles and count leftover ones, and give them a mat with the two column headings already printed. Work question 1 with them as a small group before releasing them to question 2.

Extension

Ask these students to write the two leaf-bag counts that would give a total of 70 bags when one count is a multiple of ten, then to find a second pair that also works and explain how they know both pairs are correct.

ELL supports

Pair "bundle," "tens," and "ones" with a physical anchor kept on the table all lesson, using a rubber-banded stack for a ten and a single loose cube for a one. Provide the sentence frame "___ tens and ___ ones make ___ bags" for every answer, and let students say the sentence with cubes in hand before they write.

Extensions

Keep a real bag count for any schoolwide collection drive for two weeks, adding each day's new bags to the running total on chart paper, and ask students to predict the new total before the class computes it.