Illustrative Mathematics
Illustrative Mathematics: 3.nbt, 4.nbt Rounding to the Nearest 100 and 1000
This task builds off of the skill of rounding to the nearest ten and hundred in third grade. Aligns with CCSS.Math.Content.3.NBT.A.1 Use place value understanding to round whole numbers to the nearest 10 or 100.
CK-12 Foundation
Ck 12: Arithmetic: Product Estimation With Mixed Numbers/fractions
[Free Registration/Login may be required to access all resource tools.] Estimate products and quotients of fractions and mixed numbers.
University of California
University of Calilfornia: Significant Figures Ii
This site from the University of California provides a lengthy and intelligent discussion of sig figs, absolute and relative precision, accuracy, precision in calculations, rounding off, and the whole shooting match of how we report what...