Algebra Readiness Made Easy Grade 5

A

L

G

E

B

RA

READ IN E S S

5

Balance the Blocks

Overview

Presented with clues about the relative weights of three different types of blocks in a

pan balance, students figure out which blocks will balance a new set of blocks.

Algebra

Understand that substituting one set of blocks with a second set of equal weight

preserves balance • Explore the concept of equality

Problem-Solving Strategies

Reason about proportional relationships • Reason deductively

Related Math Skills

Compute with whole numbers

Math Language

Balance • Cube • Cylinder • Sphere • Substitute • Weigh the same

Introducing the Problem Set

Make photocopies of “Solve the Problem: Balance the Blocks” (page 66) and distribute

to students. Have students work in pairs, encouraging them to discuss strategies they

might use to solve the problem. You may want to walk around and listen in on some

of their discussions. After a few minutes, display the problem on the board (or on the

overhead if you made a transparency) and use the following questions to guide a

whole-class discussion on how to solve the problem:

Look at the pan balances. What is in the first pan balance? (4 spheres in the pan on the

left balancing 2 cylinders in the pan on the right) What is in the second pan balance?

(1 cylinder in the pan on the left balancing 3 cubes in the pan on the right)

5