Curated OER
Ten Little Black Dots
Second graders use black and red construction paper to symbolize different one digit numbers that add up to 10. In this sums to 10 lesson plan, 2nd graders discover different combinations and patterns that can lead them to the number 10.
Curated OER
To a Tee
For this addition worksheet, students solve 9 problems in which ten T shirts are colored with two different colors. Students write the addition fact with the sum of ten. Students do this 9 times.
Texas Instruments
Texas Instruments: Fast Nines and Fast Tens
Students learn how to solve a mathematical equation with a missing addend. Students will learn the combinations of addends to find the sums of nine and ten. Students practice math facts with accuracy and immediacy for sums of nine and ten.
Lawrence Hall of Science
The Math Page: Skill in Arithmetic: Table of Contents
This website from The Math Page explains some helpful hints about how to do mental math.