The first KCFS project for the Grade 5 students this semester is Building a Camera. One of the special vocabulary words that students need to learn is estimate. So what does it mean to estimate?

　There are many things to measure and many ways to measure them. We can use a ruler to measure the length of something accurately, or we can estimate – which means to take a clever guess. The symbol = means "equal to" and is used when measuring accurately. The symbol ≈ means "approximately equal to" and is used when estimating.  

　Look at these pictures and estimate their sizes. All the pictures are the correct size on the page so you can use a ruler to check your estimates.