Decimals to three places · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Working with three decimal places

Mathematics · Fractions · ages 9-10
Name ______________________   Date ____________

  1. Add 1.200 + 0.005. What do you get?

    • 1.205
    • 1.25
    • 1.007

  2. 0.400 and 0.600 add up to make exactly 1.000.

    Circle one:   True   False

  3. A jug holds 2.500 l. If 1.250 l is poured out, how much is left?

    • 1.750 l
    • 1.250 l
    • 1.150 l

  4. Add these decimals: 0.45 + 0.318 + 2.2

    Answer: ______________

  5. Which pair of numbers, each written to three decimal places, adds up to exactly 1.000?

    • 0.375 and 0.625
    • 0.450 and 0.600
    • 0.230 and 0.780

  6. A tank holds 4 litres of water. Then 1.865 litres leak out. How many litres are left?

    Answer: ______________

  7. Three ribbons measure 0.358 m, 1.275 m, and 1.167 m. What is their total length in metres?

    Answer: ______________

  8. Add these three measurements: 1.234 m + 0.567 m + 2.199 m. What is the total, in metres?

    Answer: ______________

  9. Maya ran 1.205 km in the morning, 0.875 km at lunch and 0.92 km in the evening. How many kilometres did she run in all?

    Answer: ______________

  10. Priya worked out 5.000 - 2.375 and got 3.625. She regrouped through the zeros but kept all 5 ones. What is the correct answer?

    • 3.375
    • 2.625
    • 3.625
LightMySky · lightmysky.comW1-mt_sA2OvTiech-s1

Answer key

For grown-ups. Fold this page away before handing over the rest.

Working with three decimal places W1-mt_sA2OvTiech-s1

  1. 1.205 · Line up the decimal points: 1.200 + 0.005 = 1.205.
  2. True · 0.400 + 0.600 = 1.000, because 4 tenths plus 6 tenths make 10 tenths, which is one whole.
  3. 1.250 l · With the decimal points lined up, 2.500 − 1.250 leaves exactly 1.250 l.
  4. 2.968 · Zeros at the end of a decimal do not change its value, so 2.2 is the same as 2.200. Lining up the decimal points keeps every digit in the right place.
  5. 0.375 and 0.625 · 0.375 + 0.625 = 1.000. The other pairs add to 1.050 and 1.010, not exactly 1.
  6. 2.135 · Write 4 as 4.000, line up the decimal points, and regroup through the zeros: 4.000 - 1.865 = 2.135 litres.
  7. 2.8 · Adding the aligned columns gives 0.358 + 1.275 + 1.167 = 2.800 m, which is 2.8 m.
  8. 4 · Lining up the decimal points and adding each column gives exactly 4.000 m.
  9. 3 · Write 0.92 as 0.920, line up the points, and add column by column with carries: 1.205 + 0.875 + 0.920 = 3.000 km.
  10. 2.625 · Regrouping takes 1 from the 5 ones, so 5.000 becomes 4 ones, 9 tenths, 9 hundredths and 10 thousandths. Subtracting 2.375 gives 2.625. Priya's 3.625 kept all 5 ones.
Worksheet · LightMySky