BLOG

An ovary is a small organ that holds a lifetime supply of eggs and ripens one of them roughly every month. Label the resting follicles, a growing follicle, the mature follicle, the moment of release, and what is left behind, in an interactive playground.

Every egg inside an ovary sits in its own little sac called a follicle. Label the egg cell, the wall of cells around it, the fluid that opens up inside, and the shapes a follicle takes as it grows and empties, in an interactive playground.

The placenta is an organ grown just for pregnancy. It swaps food and oxygen between mother and baby through the umbilical cord, and normally sits high on the uterus wall, well clear of the way out. Label the placenta, cord, uterus wall, fluid and cervix in an interactive playground.

In the last weeks of pregnancy most babies settle head-down in the uterus, curled up in a pool of warm fluid with the exit directly below. Label the placenta, the fluid, the baby's head, the uterus wall, the cervix and the birth canal in an interactive playground.

Percent means 'per hundred', so a percentage is how many out of 100. Match percentages to 100-square grids in an interactive playground.

Pulmonary circulation is the loop where the heart pumps blood to the lungs for oxygen and back. Label the heart, lungs, pulmonary vessels, trachea and aorta in an interactive playground.

The uterus is the pear-shaped organ where a baby grows. Label its fundus, body, cervix, the fallopian tubes and the ovaries in an interactive playground.

About once a month an ovary releases an egg that travels down the fallopian tube toward the uterus. Label the ovary, follicle, tube, egg and uterus lining in an interactive playground.

Multiply fractions straight across; to divide, flip the second and multiply. Work out four problems and land each on its value in an interactive playground.

Combine the fraction method with the sign rules: do the fraction, then set the sign (same signs positive, different signs negative). Practise four problems in an interactive playground.

Each lung is divided by fissures into lobes: the right has three (upper, middle, lower), the left has two (upper, lower). Label all five lobes in an interactive playground.

The order of operations does not change with negatives: brackets, then ×÷, then +−. Work out four expressions with negatives in the right order in an interactive playground.

A nephron is the microscopic unit that does the kidney's filtering. Label the glomerulus, renal tubule, loop of Henle, collecting duct and capillaries in an interactive playground.

Every breath travels down branching airways — nasal cavity, larynx, trachea, bronchi and bronchioles. Label the breathing path in an interactive playground.

The larynx is built from cartilage. Label the hyoid bone, thyroid cartilage (Adam's apple), cricoid cartilage and trachea in an interactive playground.

Your voice is made by vocal cords vibrating as air passes through the larynx. Label the vocal cords, vestibular fold, epiglottis and airway in an interactive playground.

A square root undoes squaring: √9 = 3 because 3 × 3 = 9. Learn the radical sign and perfect squares, then work out four roots in an interactive playground.

√12 isn't whole, but it hides a perfect square: √12 = 2√3. Learn to pull out the largest perfect-square factor and simplify four roots in an interactive playground.

Kidneys clean the blood, so they need a huge blood supply. Label the renal artery, renal vein, aorta, vena cava, kidney and ureter, in an interactive playground.

The urinary system makes and removes urine along a one-way path: kidney, ureter, bladder, urethra. Label each part in an interactive playground.