DK Find Out! Heart and Blood

The heart, blood, and blood vessels form the body’s transport system.

DK Find Out! Lungs and Breathing

The cells in your body can’t survive without a continual supply of oxygen from the air.

Illuminations: How Big is Your Heart?
Illuminations (National Council of Teachers of Mathematics)

This lesson emphasizes the connections between science and mathematics by using a performance, or authentic, assessment format.