Santa Maria Maggiore church in Rome built shortly after the time of Constantine.
The obverse and reverse sides of a silver penny during the reign of William the Conqueror.
A mollusk radiate from the Paleozoic time, Pentamerus oblongus, a brachiopod from the Clinton group.
A mollusk radiate from the Paleozoic time, Rhynchotreta cuneata from the United States and Great Britain.
A mollusk radiate from the Paleozoic time, Pterinea emacerata from the Niagara group.
A mollusk radiate from the Paleozoic time, Cyclonema cancellata from the Clinton group.
A mollusk radiate from the Paleozoic time, Platyceras angulatum from the Niagara group.
An ancient mollusk from the Paleozoic time, Goniatites Marcellensis from the Hamilton group.
An ancient mollusk from the Paleozoic time, Goniatites Marcellensis from the Hamilton group.
An ancient articulate from the Paleozoic time, Pacops bufo from the Hamilton group.
An ancient radiate from the Carboniferous Age, the Actinocrinus proboscidialis.
Two ancient mollusks from the Carboniferous Age, the Productus Nebrascensis and the Athyris subtilita.
Four varieties of mollusks from the Mesozoic time: "391, Exogyra costata; 392, Inoceramus problematicus;…
The lower jaw of the Hesperornis regalis, an ancient bird of the Cretaceous Period.
A vertebrae of the Hesperornis regalis, an ancient bird of the Cretaceous Period.
A vertebrae of the Hesperornis regalis, an ancient bird of the Cretaceous Period.
The skull and upper jaw of an early rhinoceros-like mammal from the Cenozoic time.
Illustration of cards that can be used for a matching game with Roman numerals, English numerals, and…
Illustration of a child washing face at 7:00. It can be used to write mathematics story problems involving…
Illustration of a child eating breakfast at 8:00. It can be used to write mathematics story problems…
Illustration of a child going up stairs at 9:00. It can be used to write mathematics story problems…
Illustration of a child reading at school at 10:00. It can be used to write mathematics story problems…