diff --git a/pkg/math/manual.go b/pkg/math/manual.go
new file mode 100644
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--- /dev/null
+++ b/pkg/math/manual.go
@@ -0,0 +1,69 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package math
+
+import "math"
+
+// TODO: use apd
+
+// Floor returns the greatest integer value less than or equal to x.
+//
+// Special cases are:
+//	Floor(±0) = ±0
+//	Floor(±Inf) = ±Inf
+//	Floor(NaN) = NaN
+func Floor(x float64) float64 {
+	return math.Floor(x)
+}
+
+// Ceil returns the least integer value greater than or equal to x.
+//
+// Special cases are:
+//	Ceil(±0) = ±0
+//	Ceil(±Inf) = ±Inf
+//	Ceil(NaN) = NaN
+func Ceil(x float64) float64 {
+	return math.Ceil(x)
+}
+
+// Trunc returns the integer value of x.
+//
+// Special cases are:
+//	Trunc(±0) = ±0
+//	Trunc(±Inf) = ±Inf
+//	Trunc(NaN) = NaN
+func Trunc(x float64) float64 {
+	return math.Trunc(x)
+}
+
+// Round returns the nearest integer, rounding half away from zero.
+//
+// Special cases are:
+//	Round(±0) = ±0
+//	Round(±Inf) = ±Inf
+//	Round(NaN) = NaN
+func Round(x float64) float64 {
+	return math.Round(x)
+}
+
+// RoundToEven returns the nearest integer, rounding ties to even.
+//
+// Special cases are:
+//	RoundToEven(±0) = ±0
+//	RoundToEven(±Inf) = ±Inf
+//	RoundToEven(NaN) = NaN
+func RoundToEven(x float64) float64 {
+	return math.RoundToEven(x)
+}